Yea
If you want to you can, but its best to leave it till your ready to do the slayer4 quest otherwise spawning it in would be useless. Also get some mvp+ to fight for you or you will get obliterated.
Huh, wither skeleton spawners you say. My guess would be that someone just renamed the spawner, but that wouldn't explain the reason why it doesn't allow you to place the block.
When you try an connect to Manacube now, there should be information about your ban and which staff member banned you. Message that staff member on discord if you want more information.
A few years back, I was on a server where you could buy and sell items by interacting with a chest and you put the item you want to sell in the chest and a sign saying the cost and how many and if someone was to come along and buy it they could just right click the sign and the transaction would...