Attaching to the flag out line on a 4 or 5 line will increase the chance of a line inversion and take more time to reset, once you let go the bar when unhooking. Suicide mode in general is the preferred method when unhooking as resetting after you mess up a move is far easier and faster.
If attaching to suicide when unhooking, you will have a slight more tug than when messing up a move (and you let go the bar), however once the kite sits on the edge of the window in the "c" position, the pull on any kite should be minimal. If the kite for some reason ends up leading edge down after a messed up move, naturally the kite will pull a lot more, until you bring the kite to the edge of the window. Also depending where the kite is situated in the power zone and how powered up you are riding will depend on how much of a pull the kite will create when you let go the bar, when messing up an unhooked move.
Ignore the bit about the 5th line snapping that was times when I was unhooked in flag out but the 5th was wrapped a few times so took all the strain.
I can c why u'd want to be floated back to the water after missing bar. I'm not advanced though and not getting much air so for the mo that isn't a priority I'd rather just not get a hard drag through the water upside down after crashing. I know I do tend to hold onto the bar with one hand too long when bailing out of a trick (in panic) I guess I'm asking for trouble on any setup doing that
I think we found out why the kite is pulling you and why your lines are getting twisted. When you fail a trick drop the bar immediately. This is a hard thing for some to learn because it's different from hooked in riding.