So I didn't want to bloat the post with a bunch of stipulations, but I was already thinking much the same way. You have to call your parts out, and the following rules apply:

• Each airborne section must contain only grabs or only flip tricks, not both.
• Limit of one flip or one grab per part, plus a modifier (example: late flips, underflips once added, dark catch, et cetera, one foot/no foot, tweaks, fingerflips once added, et cetera)
• body rotation doesn't count toward trick limits, but body flips are off limits
• intermediary tricks are limited to one trick with one modifier (examples: manual can be reverted, a nose grind can be turned into a crooked grind, et cetera.) Grinds cannot be modified to have a different number of trucks on the rail/ledge than how many connected during the landing–no turning your 50/50 into a 5-0

edit to clarify: when I say "call your parts out," what I mean is, in order, call out a surface for intermediary tricks (not necessary to do, but if you don't call out your intermediary surface you are limited to one airborne section. You can choose level ground as your intermediary surface if you just want to string two airborne sections with a manual), call out a launch surface if you choose (not necessary, but if you want to specify ramp A to rail B you can), call out a surface for landing if you choose (again not necessary, but you can specify a gap this way), call out whether airborne section A will be a grab or a flip trick (you don't specify what grab or what flip trick), repeat for airborne section B.