See comments below
Does the strip inside sleeve move at all?
Yes it does, it's tight and you have to manipulate the strip in the flexible sleeve, but you can actually pull the whole strip out of the sleeve if you need to
Are the sleeves adhesive backed?
No they aren't
If so, is the adhesive reliable?
Haven't tried adhesive, but FrankR hot glued the strip to PVC pipe, I just zip tied mine to PVC pipe.
If not, how would you mount? RTV or special stuff?
I know RJ recommended sealing the cuts with RTV but what is best way to do that? Solder wires and just get some RTV in sleeve and let dry? (extra points for pictures) I am contemplating some shrink wrap with the RTV. Overkill?
Not overkill when it pours down and it shorts out you SSC on the peak of the house and you have to climb up to fix it.
What I did was slid heat shrink over the end of the strip, and then filled it with RTV. Then when I shrank it with heat, it squeezed the RTV out of both ends of the heatshrink. I'm confident that water will not get in the ends of my flexstrips.