What I've made as a habit is to auction recipes, get used to memorising which recipes are worth it and always sell for marginally lower then current buy out price. (I always make mine 100 cr lower)
I tend to spend at least 150k+ CR on recipes a day, the next day I'll have 170-200k
I NEVER go to sleep without having less then 5k cr on me, I will always have the most amount recipes up in AH that I can get.
It's just one of those things where you have to invest a lot to make a lot.
A little warning, don't make the mistake of buying a bad recipe, as one bad recipe could make you're net profit negative

To refute your argument on guns, I've had a Nightblade and a Faust, but I've found that the Shadowtech Alchemers are the best kind of shadow weaponry for my playstyle, considering the mobs you deal with, especially in T3. Jellies aren't really a problem, but they do tend to mob up around you and attack much faster, and that would be the only instance of me using a shadow sword to quickly dispatch of them. But I find Gremlins far more difficult to deal with, due to constantly running around and being in even greater numbers than Jellies (assuming you're not just lounging around in Jelly Palace all the time) and having far variable tactics. It is -essential- to kill Ironclaw Menders ASAP, as they can negate almost all damage you do to surrounding mobs, but more often than not they are constantly surrounded by stronger, more vicious mobs, and- especially if you're going solo- finding a safe opening takes a lot of time and risk. Using guns effectively reduces that risk by a long shot, being able to pick at them through crowds without jeopardizing your precious health (and in T3, not losing health should be your number one priority). The Alchemer line is also superior in terms of dishing out long range statuses and elemental damage- you can easily replace that Shadow Driver with a Cryo Driver and just freeze enemies in place instead, while having the added ability to total constructs like Lumbers and Gun Puppies at a faster pace.

Like with most gun arguments, its a matter of DPS vs survivability.

The point of the magnus line is that it's auto-aiming so long as you point in the right general direction, and that it's fast enough that even pretty agile mobs often can't dodge it. The downsides are that it really can't pour in damage very quickly, and a lot of mobs are highly resistant to pure piercing damage. Your master blaster should work well against gun puppies, lumbers, and retrodes, but a magnus is nearly useless against those mobs.

I love my umbra driver and use it for most enemies, and I can say definitively that guns are awesome. Firing a charge shot into a group of enemies or abusing enemy geometry (like lumbers) so one shot hits multiple times is incredibly satisfying. Whatever the umbra driver doesn't handle, my argent peacemaker can. I'm likely to level up another alchemer as well.

Well, except for T3 wolvers who are jerks and like teleporting next to you. But even that can work to my advantage by warping them away from packs of enemies and then slashing them to bits with my dread venom striker. But that's pretty much the only time I "need" to melee at all.

Tips or Tricks for getting money.
You need money to make money. A large portion of players' income comes either from merching recipes in the AH or from masscrafting for good UVs. If you only have 3000cr, you can't expect to buy a good recipe and sell it for 7k profit later, can you? In T3, you want to have at least 30kcr on you at all times, and preferably 80k in case you run into a really good list from Basil.
You only get so much money from the clockworks, and that requires a heavy time investment, and when CE costs are factored in, you don't make too much profit. Recipes cost no time and a very good source of income.
T3 for mats, but bad for crowns?
All even stratums (the ones after terminal) give more heat than their odd counterparts, so you make many more crowns in Stratum 4 (end of T2) than 5 (start of T3), likewise Stratum 2 (end of T1) is better than Stratum 3 (start of T2). T3 offers much better 5* mats like flame souls, philoso feathers, heavy gears, etc. However, if you can't survive stratum 6, I'd suggest you just stick with T2 so you don't waste energy reviving--it quickly adds up, and I refrain from CE reviving even if I'm solo; it's a better idea to just return to haven, since chances are, you'll die again and waste even more having to revive.
Guns, bad?
There are plenty of a-holes who will immediately kick a gunner for joining their party and don't attempt to hide their hatred for all gunners, just because they ran into a few noobs early on. Gunning when done right is like mastering an art form, which is why most people suck at it and go back to swords. However, the new Pulsar is an excellent hack-and-slash gun for those of us who are less refined in our 'gunslinging'. Guns can be lifesavers when used properly, but can also enrage teammates when used improperly, like knocking away the mob they're trying to kill. They're perfectly capable of handling 1 or 2 simple monsters, so turn your efforts to the swarms on the other side of the map. It's like having someone charge their calibur and knock a lumbar into you, causing you to die. I'd rather they didn't screw me with their carelessness.
As for what you said about enemies that dodge, it's only true for wolvers and fiends, gremlins maybe. If you use a gun that shoots fast bullets, usually you'll hit them before they dodge it (and you can also aim your shots to make them strategically dodge into corners or away from overwhelmed teammates). All other enemies are slow and great to use a gun on since it keeps you out of the fray and deals good damage / crowd control if you do it right--for example, trying to use an antigua on jellies is just dumb, but polaris in graveyards will save your life several times over.
Do I need a sword?
Snarble Barb is a silly back-up, since you want your back-up weapon to deal normal damage while your mains cover the other damage types (Piercing, Elemental, Shadow). A back-up is precisely that. For your primaries, get weapons that you can use and are good in whatever situation you anticipate, but the back-up should be precisely that. I'd suggest a Leviathan since it's a good, standard sword, but your back up can be another gun if you're dedicated/good enough for that.

Snarble Barb is a silly back-up

Yes, but it's an excellent primary weapon to complement elemental and shadow guns.

It's only silly for your "back up" weapon to be a special damage type if you only have 2 weapon slots. If you can cover all three damage types, you do so. Then it doesn't matter what enemies you face, you just switch to the appropriate weapon and tear them a new one. I do fiend strata with a Snarble Barb, a Kilowatt Pulsar and a Shadow Driver, for instance. Fiends get stabbed, everything else gets shot. In fact, once you have a good idea of what turns up in the various level and strata types, you can often get away with only covering 2 damage types. Anything that resists one will be at worst neutral to the other one, so it's just like carrying a normal-type weapon anyway. The only time this is really a concern is when the weapon that carries the damage type they don't resist is of a class that is difficult to apply to the monster in question.

For instance, I wouldn't want to run into Devilites while carrying a shadow damage sword and a gun as my non-shadow backup piece, as trying to gun them down is irritating at best. By the same token, I feel better about killing certain kinds of enemy from range, as opposed to trying to get up in their faces.

As a further example, I carry exclusively Shadow and Elemental damage weapons to both the Royal Jelly Palace and the Ironclaw Munitions Factory. To the IMF I carry a Faust, Avenger and Kilowatt Pulsar, and to the Palace I carry a Faust, Kilowatt Pulsar and Shadow Driver. The Shadow Driver is an awesome weapon for taking on the packs of jelly cubes in the mostly open Palace, but the only thing weak to shadow in the IMF are a couple of gremlins and some quicksilvers, both of which are better approached with a sword, especially in the tight spaces you occasionally have to fight in.

The only real argument for carrying a Calibur series sword is that it's easily applied to just about anything, and its charge attack is awesome.