Q1 Answered in No32 book. Q2: Purely a matter for you. De rested is de rusted is de-rusted in my opinion. Q3 If it ain't broke, don't fix it. (But you WILL break it if you strip it). Q4 Generally, changing a scope in a bracket is FAR easier than changing a bracket on a rifle. But there will be many more questions to ask before you do. And this has been asked and answered a zillion times on this forum. Q5. After derusting, phosphate and paint. Q6 You CAN leave a chipped lens in place if it's in the outer third of the optical field. But with special precautions. Q7 L1A1 turrets readily available - if you have VERY deep pockets. Q8 If I might be so bold and a tad undiplomatic as to say, that's a silly Q! Of course it should keep its zero. It'd defeat the object if it didn't! Q9, read answer to Q4
If, as you say, you're a beginner, then I would start by practicing on a crap Mk1, read and digest the book and everything possible on this site