You might want to read up a bit on what latency is and what causes it. Latency isn't a fault in programming. Neither are the effects.

TL;DR on causes:
YOUR geographical location.
YOUR Internet service provider.
Overloaded servers.

Do note that overloaded servers aren't an issue here as that'd create issues for EVERYONE but that's not the case.

TL;DR on effects:
You posted them as "bugs".

As for the devs relation to the game, you might want to reconsider it. How do you think you would feel about something that you dedicated eight hours a day to for three years? Try just working a lot on a game, a painting, a song, or anything for just a month and reconsider that statement.

Not necessarily. If OOO's server generates the level and mobs before it's player, you could definitely remove hacking with say, crowns from the mobs. It'd definitely be more vulnerable but I think it could be done. Warframe does it, so why can't SK? :D

Developers want your money, but you ain't forced to pay. The game is free in the end.
It's also easy to say "i want this", but how would you do it?

Maybe developers don't have the experience. Maybe they are working on too many proyects at once.
That doesn't mean they don't care. Make your own game and see how easy it is.

A quick fix for that would be ensuring currency/mats are server-side.

Correction: it would guarantee* lag. People tend to have worse connections than dedicated server machines. That aside, it'd mean people far away from Europe and the US would be able to have good connections.

*does not apply to hosts with good internet.

Don't diss software devs, being the smaller team that OOO is, I'm sure they are working pretty damn hard. There is a grain of truth though, when you know the inner workings of what makes something tick, it loses some of its magic. That is why testers and non-dev QA is important. But back on topic.

I am curious how SK handles latency, because many games use a predictive model where the client begins calculating and animating a few hundred milliseconds ahead, checking in with the server to verify. Specifically:
When you fire a gun, or move somewhere, the client on your computer immediately begins animating that motion after it sends the command to the server. If all is well, a hundred milliseconds later the server confirms that yeah, you successfully performed that action and you are none the wiser.
The problem is when that lag-time grows too large, or some chance even just happens to interfere: for example, on the server a wolver teleported next to you and blocked your way. You may have moved a tile to the left, but when the server confirmation comes back, the client snaps you back to your original position because the server states you were not in fact where the client thought you were. Another way this could happen is if the packet containing the initial "start moving" command got dropped.
Finally, if this gets bad enough, the client and server can get utterly out of synch, resulting in the kind of thing where you get stuck/rubberbanded in place while monsters and party members go walking off into space, ultimately resulting in a disconnect.
The periodic position corrections I experience, as well as the wholesale desynch that happens occasionally suggest to me this is how SK handles natural latency. I suspect all of these new objects and increased movement speed have something to do with the perception that lag is getting worse; in the old days, there wasn't nearly as much going on in a given instant.

I am a little hard-pressed to explain the bullets changing course though (which I have definitely experienced). Perhaps the fire command is tracked separately from the cursor location, and the cursor location data gets processed first on the server side, while the client doesn't have to process them discretely so just assumes you are shooting in that direction. Then, because the server received the updated cursor info before the fire command, it sends back confirmation that you fired in a different direction, and the client adjusts your bullet mid-flight.

If the devs are willing to be more transparent about this, I would love to hear. :)

I would actually defend OP's position. Why? Because "it's a small team" is never a good excuse, seeing my Mega Magnus bullet home on devilite I tried to shoot is both funny and sad, having ~20-40FPS (And ~10-30FPS in Shadow Lairs. Seriously?) in most dungeons, and ~70 in empty guild hall is ridicilous and on top of all that - game quite prone to freeze when lag spike occurs.

Seriously. And that's on same computer who runs games like SASRT, Warframe and MK9 at full speed just fine, and yet lags in game with 2D-Doom level of complexity

If it's "faulty coding from unexperienced past me", it's time to redo thing from all over again. Even if it's not, still, game would benefit from optimising. And player-hosted dungeons too.

Edit: And "OOO don't have resources"-point. Unless Energy pack money and stuff goes directly to Sega, they should have enough resources to afford at least one more server, and even then, OOO is Sega's company, don't they should fund them too? Or it's just one-way money vaccum?

And one more thing - make Preview thingy in gear stats optional. It's pain to scroll through. And I can't see whole list of materials I need to craft gear with it

*cough*

If you say 'most people' without backing that up with actual data from polls, it reduces your credibility to zero, and basically just shows that you don't know how to spell 'in my opinion'.

Your definition of 'normal' also is, well, you not knowing how to spell 'in my opinion'.

Most of the stuff you list does not happen to me. Therefore it can not be the game's fault.

I do experience weapon changing faults, I expect it's my keyboard (I refuse to bear the windoze keys that are on all newer ones, they just get in the way, thus my keyboard, which doesn't have them, is somewhat geriatric).

I do get AH (and just Haven) getting a bit slow after being in the game for a while. As that's not in the middle of a run, there's an easy solution: close the window and restart.

So, I (speaking for myself, I don't claim to know what some random vague 'most people' want) am happy with the gods of SK working on the stuff recently announced to be coming.

Ragnarock, the bit about 'most people' also applies to you. No arsenal in an enemy lair consisting of consecutive levels may be your problem, but where you go is solely your decision.

SK does much heavier graphical stuff than Minecraft. Sure, it's terribly programmed but it's still so much more simple than SK. Most notably, you'll find that SK has textures bigger than 16x16 pixels and models that aren't bound to rectangles.

Hum, I don't experience many of these problems, not even on my very old computer, and definitely not on my shiny new computer. The rest is latency (although I almost always have 4 bars, so I wonder sometimes if their latency meter is broken...)

Just because they made an announcement about whats in store doesn't mean they aren't still working on actual bug fixes and the like, that is an ongoing never ending battle for developers.