Burning paint certainly does have something to do with technique, but it is also very much the tool. Anything with forced rotation can burn the paint, so that's something like a full rotary or a Flex 3401 (the 3401 being the lesser of those two since it is a forced rotation dual action machine). Random orbitals like the Rupes are extremely safe...about the only way you can burn the paint with one of those is if you are really trying. I guess you can also damage the paint if you drop the machine on it.
Keep in mind that the Rupes machines are a system, meaning they are designed to be used with their backing plates, pads, and polishes/compounds. I've never personally used one, but I don't like the idea of being married to a single source for pads/polishes/etc. if you want the best results. That doesn't mean you can't, it just isn't recommended.
I've owned a PC7424 since the early 2000s, and it still does a great job in most cases. I just picked up a Flex 3401 this year, and it is a much more powerful machine for sure. I'm about ready to pull the trigger on a Griot's machine to replace the 7424 - I'm not expecting night and day different results, but their newest machines have some very nice features that would be very nice to have.
Whatever you decide, see if you can find a machine with a 25 foot long cord. I ordered my Flex with one, and it is SO nice not having to drag an extension cord around. The Griot's machines also have this option.