Hi Matthew
Removing scratches, from clear plastic is not easy. Haven't tried it myself, but have read about modelers who have removed scratches with sandpaper and/or polishing compund. The sandpaper, of course, needs to be very fine(Grid 10000)some dunk the item in Future after polishing.
Painting: first of all, you need to prep the model far better than the average military model. Gloss paint will not hide any scratches or imperfections. Prime the model, check for imperfections. When shooting the color coat, first give it a mist(very light coat, that does not necessarily cover the primer) wait untill the paint is semi dry(Tacky) then shot another coat. 3-4 light coats is far better than one thick coat. Some make the final coat a wet coat. Making the final layer so thick the paint will level it self out, but not so thick it will start to run. This gives great results if you can handle it. I will suggest "many" light coats. Perhaps give it a rest after second coat and check for flaws. If you need to remove flaws, don't use any rubing compund between coats. Any residue can react with your paint.
Clearcoat the same way as with the color and polish when dry. I ussually wait a week, or more, before polishing. I use Meguiars scratch X and wax(Can't recall whitch one)
Using BMF or not really depends on what needs to be chromed. BMF is superb for various straightline chrome trim. BMF is not good for a 1950's bumper or grill, valve covers, alternator or similar stuff. Here Alclad II chrome will be the one to use.
Hope this is helpfull. Looking forward to seeing your shiny work.