Right now it's not really possible. I assume it will be a feature in the future, but for it's not a thing on lemmy. There is RSS links I believe on user pages but they seem to be finnicky.
Unfortunately it is only instance wide at the moment.
I looked at mine out of curiosity and holy cow. Yeah, something is up. I think it might be a lemmy 0.18.0 thing.
Yes. As well as kbin.
We will have a warning that pops up stating the site is for adults only and requiring you to click yes to access it.