We're not removing paint, we're just not adding 500 new paints, its just not possible. I'm sure skin packs that replace certain textures will be possible at some point so users or mods can change the textures out.
No its a big atlas. We stream individual textures like zombies, block entities like doors, forges, coffee makers, etc. But paintable blocks all use the texture atlas which cannot stream. Even if it could it wouldn't offer much benefit there is almost always a block in view which would require it to be high res.
There is no doubt if you get to late game you will probably end up doing some painting, unless all you care about is pure game mechanics.
So I smashed my day 21 horde no problem. 24 alive and had them all dead by 12 something. THen I go to a T5 poi and its all going smooth and I walk into a bathroom and guys fall from the ceiling so I try to back pedal out of the door way and I can't move. I start hearing the sounds of iron armor getting smashed, and see stun and stuff, turn around and I'm sandwiched in by half a dozen zombies at my back. I tried moving forward shooting guys as fast as possible with my sawed off pump shotgun, but it was too late, I got wrecked. Now I have to pedal my bike back to get my stuff

Oh well it was fun, getting wrecked can be a strong motivator... time to get some better armor I think. I've stocked up a lot of parts but I don't have any perks yet so I'll level up my armor skill and start making some better armor.