First Welcome to KiteLife.
You've made several observations but they don't necessarily line up with each other. Both the "stop and pop" as well as the slack line stuff and even freestyle can be done on both long and short lines. Urban fliers and those that fly in tighter areas tend to use short lines. Long lines can be precision or what we call soul flying.. so both styles are also both lengths. Longer lines 120's are typically used for team flying as well. Longer lines tend to give more reaction time so lend well to relaxing flight patterns..
The Djinn, Detox, Polo, Phoenix, etc. are similar to the Rev with each having individual characteristics that influence flying. Keep in mind Rev held market exclusivity for many years and only in the last few have the other designers and creators been able to market their "improvements"
I'm not knocking Rev at all Joe Hadzicki designed a great produce and wing. There are just new developments incorporated into other designs that lend themselves to different performances. ANY of these wings can be freestyle and any can also be "pattern" flying or team..
That was a very convoluted and drawn out way of saying, fly the style you like, with the kite you like and the line length appropriate for your space to fly in.
Venting is usually chosen based on wind conditions but outside of that everything is pretty much personal preferences.. The good news is there's really not a wrong answer. The bad new for your pocketbook is there's also not a songle good answer but there are a lot of right ones..