Painting Kitchen Cabinets -- need help.?

first before you sand or paint them you should degrease them no matter how clean your kitchen and you cleaning is there will still be a chance that there is ingound grease [no offence]

fill the scratches with a good quality filler and then sand the whole doors etc.

prime with a good quality paint undercoat then top coat sanding between coats lightly and use a second top coat after lightly sanding for a deeper finish

Yes on the bondo, NO on the liquid sandpaper.

It's REALLY time consuming/ annoying to sand all of your cabinets, but it HAS to be done. You will totally regret it within a year if you don't! You can purchase one of those small sanders at Home Depot form pretty cheap- $30-50- and that'll help save your arms!

Yes Bondo would be my choice, it dries fast and hard you can sand it down in just minutes. Just don't make too much at one time because it will harden fast. I have used for years as a finish carpenter and with no problems of cracking or losing adhesion. Buy at an automotive discount store not from a home improvement store they jack up the price a little because it is not an everyday item but it is at an automotive store.

My advise is to reconsider this. Since your asking question of this nature you going to have a time getting good results this is not as simple as it sounds.

If you must Durham's rock hard water putty is a better choose for the filler as it is water based, lighter and easier to work with then bondo

Idk