Hi, and welcome to the forum.
A munter hitch has one leg crossing another at 90 degrees. A munter hitch slips easily. Therefore the two legs create a lot of friction when the line slips. Not good. Heat will melt most synthetic fibers, and you don't want additional wear to your lines. I'm not a single line guru. I'm sure others will chime in with advice. It would better to not have the line cross itself.
Twist will inhibit the performance of any line. It is acceptable to a degree, but it is exponentially detrimental. Twice as much twist is four times as bad. Browse the single line topics of the forum also. I've seen a lot of big kite line discussion there.