Ok so ive been playing Linne for a week or so. First of all, im pretty sure 2A is not a low, which would make 5A better to use in combos because of its extended range and use 2A to whiff cancel. So as high/low mixups, you should start your lows with 2b.
If you are midscreen, 63214B will most likley go over the opponent and land you a punish so be carefull with that mid screen unless yo are sure about the spacing. But if you hit 63214B in the corner, im not sure if you can normal combo off it but you can easily CS to get around 4k damage if you do 63214B>CS>5B>5C>2C>214B~A> j.B>j.6B>j.C>j.2B>2C>6CCC after this you can either do high/low mixups with assult or your double jumps faking over heads or hitting a double overhead or you can follow the 6CCC with 236C for more damage and then do mixup of go for B+C>a/b/c for about 1-00 more damage. Witht eh B+C its about 4.2k dmg.
If you are midscreen, a good mixup is to end your combo after 6CCC with 236C which will make them air tech and from there you can read were they will tech and try to go for cross-unders or fake cross-unders after cross-under/fake cross-under you should do assult or 2B to do high/low mixup. Keep in mind that with fake cross-under assults you can easily be dped if they read it correctly. You can also grab or bait dp besides high/low.
I think air kuuga has a little bit if invincibility because ive been using it when a hyde does an anti-air dp on me and it always seems to go through me but the kuuga sometimes hits the hyde so thats pretty cool .
Thats all i can remember right now, ill keep updating with new tech.