yes, t8 is master and used for fx in all compositions, from the dramatic to the subtle.
in your case you have an option i don’t have – to run up to four ar outputs into the ot and process/sample them individually, potentially using them as an fx send using the cue outs as well. i get curious about the possibilities of this approach from time to time but i never explore it because my inputs are all taken.
if i didn’t have a kp3 no doubt i’d spend far more time using the ot for transitions. once you’ve got the basic ot transition trick down, you can start to imagine creative variations – for example, in your case, what if you sampled three separate ar lines into three different track recorders and then had each of them running their own track lengths, eack with their own fx settings? … just imagining stuff like that gets me salivating.
the flipside is, the more planning of this sort you do, the more it kinda implies that you know in advance what composition is going to follow the current one. (i.e., a complex transition like i just described might work great as a lead-in for one jam, but it may sound dumb with others.) ymmv of course.
some artists do plan their sets in advance and it would be fine for them. i don’t however, so i need to give myself the maximum possible flexibility, so i can take the set where i like from one jam to the next, as a dj would. that’s the big reason the kp3 works well … while it’s looping, i can load up whatever seems appropriate and fade in the right elements. far simpler, but far less thinking involved, which for me is crucial with an audience. 
i know that conceiving what you want to do and executing it in a way that presents no future stumbling blocks is a major part of this process, so hope all this helps.
lots of your ideas and at least one of your 1-cycles are in there!
