Quoted from shadetree77:-Will the protector lay down correctly on top of the mylar that's on there? Particularly around the edges and the parts where the mylar is sort of stacked?
Yes it will work great!
-Keeping in mind that the playfield is planking a decent amount, will the protector affect it negatively at all?
No it will protect what is left forever.-Also, am I correct in thinking that the protector has no kind of adhesive on it at all? If so, what exactly holds it down? Is it like a window cling sort of thing? Or does the weight of the material combined with playfield pieces hold it in place?
The weight of the material keeps it in place, you may have to remove flipper bats, ball gates, etc. to install.
-If I do put a protector on, should I wax the playfield first?
Yes absolutely clean the playfield and make sure there isn't and dust or debris on the playfield prior to installing.