AKradian

I just tried equipping a Zakum Tree Branch on my Hayato, and was able to switch back to my Katana with no problem.

Do you have a free slot in your Equip inventory?
If not, make one, and then double-click your Katana. The Katana should be equipped and the Zakum Tree Branch and your Kodachi (secondary) will be unequipped.
You will need to re-equip your Kodachi after that.

She means you need to make a free space in your Use inventory.

This issue was reported with the nodestones in previous coin shop but I guess it has not been fixed yet. I will forward it again.

Interesting. This is not a problem I've heard of before.
Are you suffering from any symptoms listed here: http://forums.maplestory.nexon.net/discussion/151/memory-dll-corruption/p1
If so, please do a full shutdown and restart of your computer, as explained here: https://www.howtogeek.com/129021/how-to-do-a-full-shutdown-in-windows-8-without-disabling-hybrid-boot/

If that doesn't help, can you try to add details:
- What exactly do you mean by "kicks me out of the party/queue"? Do you get any message?
- What exactly happens when you try to turn in the hungry muto ingredients? Does it happen with every ingredient on every run?
- Does the issue happen even with just one bunny equipped, or only with 3?
- Do you have any other pets with a buff? Does the issue happen with them as well?

chooz wrote: »

I imagine this is intended behavior, that the game auto-quits when the number of people present drops below the minimum amount to play the game, to prevent people from getting easy wins

I don't think so. People who use mules to artificially raise the participant count, gain nothing by taking them out of the game early.
I believe it is as OP said, the game is simply coded to compare the number of people in the room with the number of people on the board, and end when they're equal. The programmers didn't take into account that it might not be the same people.

I have forwarded this issue.

If you have 3 physical computers and you're operating them all yourself, then it's not against the ToS.

However, should a GM whisper any of them, you need to be able to respond in reasonable time, or the GM might think your character is being botted (i.e., keyweighting or other AFK functioning).