Questions about starting with resin printing

Hey there,

I've been doing a bunch of printing with FDM printers for the last few years (for structural stuff, cases for electronics projects, but no miniatures/models/etc) , but I was looking to get a resin printer, mostly because I would like a few parts printed in translucent, but also wouldn't mind popping off a few models that my daughter wants to make from time-to-time.

I have a few questions before I pull the trigger, and would appreciate any advice.

- Why is the predominant color that I see things printed (admittedly, while watching YouTube) all in the gray - is that just the best 'canvas' for things intended to be painted anyway? If I bought white and wanted to paint that, is there really much difference?

- is tinting resin yourself a thing? I see that I can get much better deals buying resin in large quantities - if I buy a lot of say clear/transparent, can I use tints like I've used in epoxy resin casts?

- same thing goes for solid color - if I buy some white resin, can I tint that, or is that a really dumb idea?

- are the "ABS-Like" resins worth the upcharge? If I want to make a few tough pieces, is that a good idea? If I buy that in large enough quantity to get the price down, is it OK to use that for everything?

- Is it recommended to get that "bio-resin" for prints that are intended to be worn?

Really, any other pro-active advice about resins is more than welcome.

If you were going to buy 30-ish kg of resin for a starter kit, what would you get?