Sure, not sure how much response you will get for playtesting, but it cannot hurt to ask or at least throw some ideas out.
Sure, I might want to do both, so also provide a link to where you are marshalling. At least when you are ready.
What basics are you thinking of? Would a character be aware of monsters and magic off the bat? How much of the core are you using? Are you changing any of it?
What do you want advice about specifically? My world is homebrew and has been for over 25 years.
Thread that goes "bump".