I'm also gonna ask a few questions, if you have the time lemme know answers. Sorry if they've been posted before, I did look at the stickied help links and topics and such but these were the ones I wasn't able to get answered.
-Is there any way to remove accessories without destroying them? This seems pretty harsh ;( I didn't know when I attached my proto crest that it was gonna be stuck on my fencing coat forever. I already ran into an armor whose appearance I like more.
-I saw something that seemed to indicate that playing with multiple people in dungeons is more profitable. However, it seems to me like I am a little better off playing on my own, because I don't die (atm!) unless there's severe lag, and that means all material drops become mine. Does having more people increase the number of monsters/crowns/heat/whatever?
-Is there a way of telling the number of floors a ranked mission will take? The wiki doesn't seem to list this information.
-Any use for recipes that I've already learned besides unbind and sell? (which seems counterproductive, at least for the ones I have)
-Expansion Players: How fun is this compared to the rest of the game's content (like new enemies and maps: how cool are they?), and is it significantly more/less tough? Is tier one expo about as tough as tier 1 arcade, etc? How does the variability of the expansion gate compare to the arcade gates?
Also, I like tabbing people, but I wish there was some kind of refund or something for when you tab someone and then they leave as soon as the next floor starts. It's discouraging me from helping other people out :(
I'll try to answer everything in one go
1. There is no way to remove accessories without destroying them, this is why you really need to think about what ur putting them on. Sorry but thats just how it goes :\
2. Playing with a group is almost always better as you all get equal amounts of crowns and you also get more heat. You may not be dying now, but from tier 2 onward its always better to have a buddy with you to help you revive, plus, if you revive someone else, you get some more heat which is always great. Also, the more people you have, the larger variety of minerals you get as well; everyone gets the same amount of minerals so if there are three people and one has a purple, one has a red, and one has a blue, everyone gets purple, red, and blue minerals.
3. You can find out how many floors a mission will take by going into the menu (its the gear icon if i remember correctly) and mousing down to "gate map." You should be able to see how many floors a mission will take, plus the route you have taken if you were doing arcade.
4. I dont really understand ur question...if you learn a recipe, thats it. It will be located in your crafting machine and you can use it as much as you want. You can't unbind already learned recipes.
5. I have played operation crimson hammer, and its pretty damn awesome. The items you get are cool and its overall a fun few levels. The expansion's tiers work exactly like they do normal game so you wont be getting insanely hard enemies at tier 1, much like you wont get insanely easy enemies at teri 3.
6. Sorry, theres no benefit to tabbing ppl besides the feeling of gratitude. So yeah, unless you have a huge stockpile of crystal energy, dont tab.
I hope that answers your questions, have fun playing Spiral Knights! :D