Hi there! I actually would say that you should go ahead and keep practicing to do freehanding with drawing in general, rather than stick to a base. I feel like you'll learn a lot better that way as a base can possibly become a crutch? Although it can be a learning experience, I think it'd be better for you to just straight up draw digitally freehand. (Unless you're currently only using a mouse? In which case I could understand) Even if you're not confident enough, I think you should just go for it.
Right now, I feel that I can't really critique this since it's modified from a base, so I'm not sure which parts you've done and which parts are from the base. I will say however, that the anatomy on this is a bit wonky. I wanna know what you're going for first though, since I know not everyone does full on realism, but there should be a degree of fundamentals I think for the art you're going?
I can link you to some anatomy resources if you'd like! I have so many bookmarked and saved lol
As for your questions, I think those are more based on your own preferences than really like - something I could critique on? You could anti-alias the lines if you're looking for something smooth, but you could also keep it pixellated if that's what you wish. You could do cell shading if you want, or just smooth shading if you wanted to. It's really up to you, since those kind of qualities people have made adopts with before. I'm not sure what you mean with effort though, but like - for now it seems like you're just going for regular/nude bases as I don't see a design yet.