Ok, do not shoot me here...some basic questions.
1. why do we use flaps in the first place?
My understanding, from lots of reading and very little plane building, is that it makes for a smoother looking square corner. It's debatable whether they're actually necessary, as apparently folks can build flapless planes that corner square just fine -- except they don't look as good doing it.
2. Even the B-2 has flaps and it has no conventional horizontal stab.
The "flaps" on the back end of a flying wing are the elevators. High-lift devices on flying wings are restricted to leading edge slats, drooped leading edges, and maybe vortex generators (turbulators).
3. Does the flap increase lifT as speed drops? As in when you change direction. the lift is no longer in the direction the a/c was prior to the change in control surfaces movement. Not sure I'm explaineing what I mean clearly here.
A flapped wing will generate more lift before it stalls than an unflapped wing. It'll also generate lots more drag. I
suspect that the biggest thing that flaps do for you in control line stunt is to lessen the need for extreme pitch angle on the square corners, and generating more lift is only the second-biggest thing.
Flaps also give you the opposite pitch moment than what you want -- drop the flap trailing edge and you not only generate more lift for a given pitch angle, but you also make a pitch
down moment which has to be overcome by the elevator. This leads, if I'm not mistaken, to the need for the relatively enormous horizontal surfaces on flapped stunters vs. just about everything else in all creation.