Ha, welcome to the wormhole, full of wheels, fluff, yarn and other lovelies designed to remove all your money and time
To answer some of your questions, I'm spinning silk on one of my wheels at the moment, which is like spinning water, amazing
I've dyed with some natural dyes that I could collect around here and I've microwave dyed. Both are good fun.
Mainly i spin wool. I've just got a good longdraw going, but though I find it great fun to do, I don't really love woollen yarn and prefer what I spin with a worsted draw.
I've got the 'Guild challenge' stuff to spin for now, and then I want to learn to spin a boucle yarn
I will be learning and playing for years
Oh and i'm saving up for a drum carder too, so I can process my own Shetlands fleeces and spin them