neoflex- I hesitate to comment on Menzerna's polishes as I haven't actually used them. But anyhow, *IF* you see marring (swirls, scratches, "cobwebs") then new or not, you oughta use a polish to remove/reduce them. If you do NOT see any marring, then there is no need to use a polish. If the Intensive leaves (fine, "micro-")marring of its own due to its abrasives, then you need to use something finer afterwards, like their Final Polish. The AIO will *NOT* remove any marring, it's just a cleaner. So get all your polishing done BEFORE you go to the AIO.
Jliao- Doesn't matter as long as your paint and the pad are free of abrasive contamination/dirt. *IF* there IS something there between your pad and the paint (or if your pad is dirty) and you DO get marring from it, then going front-to-back will minimize how noticeable it is. But if everything is as clean as it should be, you won't get any marring anyhow so it won't matter which motion you use. It's like when people use a PC- IT sure doesn't go fron-to-back, yet it doesn't mar the finish.