I do believe you can do some of the stuff you're talking about - forcing rotations, backflips etc - that stuff you can do when you have a background doing similar tricks in other sports.
However, I think you're also shooting yourself in the foot right now by trying tricks with bad basic execution technique because you learnt basic snowboard technique then jumped to freestyle without bothering to properly master it.
It sounds like what you're doing right now is forcing rotations and trying to compensate for the sketchy basic carving/timing technique because you have good aerial awareness and solid rotation skills.
What you need to do to spin smooth 360s and more:
Go work on your carving and spin initiation and release. Even if you're carving now after 6 days, I'm willing to bet your edge to edge carving technique is still sketchy, especially as you reach faster speeds, which is why you can't get enough rotation on your 360s.
You can continue to force 360 rotations if you want and leapfrog properly mastering carving, but man will your spins be ugly and cringe worthy.
Can you learn to backflip and land 360s in a week? Absolutely.
Should you learn backflips and 360s in a week? Almost never... unless you want to be the guy with the worst looking tricks in the park who always looks like he's about to crash.
Not to mention you're killing yourself later when it comes to bigger tricks like 720s and beyond that REQUIRE mastery of carving and other basic techniques.
^ Thank you for something I was looking for
I appreciate these tips, Ill just leave backflips to side hits for now and Ill continue park, but I will definitely start spending more time on the slopes improving my carving. As I think of it, that is probably my problem with the 360s. I will continue to push myself on the jumps, just airing them for now. And Ill keep it up on the rails and boxes.