a) relatively low/moderate damage as well
b) weak whiffpunishment, when Leixia spaces incorrectly and her evades get stepped
c) relatively slow
d) short-ranged, because Leixia is very bad at spacing, whiffpunishing and blockpunishing long-ranged moves
e) poor tools to shut down movement
True.
I do think Astaroth has those weaknesses though which is why I think the match-up is not too bad. NH damage, actual whiffpunishment (not guesses with 22B), speed and anti-step are bad for Asta. Range is better but his recovery on ranged moves is bad making it not a chore getting close (unlike vs Mitsu or Cervantes where it is borderline ridiculous trying to getting in range)
Some other things:
Natsu can punish 3B and FC 3B with A:6, meaning you have to use low damage pokes only against her (a whopping 56 damage off FC 3B is too much for this match-up). Leixia has advantages but any whiff and Natsu can kill you fast.
Yoshi is a solid character and does a lot of damage. Even 6K, which is a pretty risky move, becomes viable because Leixia can only punish it for 41 damage unless she has eneough meter and is willing to use it. However having FC 3B to punish FC 3K and Dragonfly K is nice for Leixia in this match-up.
Patroklos only needs one good read/guess to hit you with 66B or B+K. He's dealing double to triple damage with the same kinds of pokes and crushing moves. Sure Leixia has CH 66BB, but if they just block and step? Death to Leixia.
Xiba is in no way bad. He is extremely solid and does masses of damage from his bread-and-butter attacks. Against Leixia he takes little risk in going for his huge rewards. I've played Xiba loads, one of our top players over here is Grunt Dude (you can watch him in the Edge Master Series tournaments we had over here) and I don't even bother using Leixia against him any more, I can't get a round.
Killing WR B BE has really hurt Leixia badly. The move had the potential to completely ruin certain characters' mix-ups and strategies. Leixia was a broken bitch before the patch, but more than half the cast are like this now. She was a decent character pre-patch and got nerfed over and over again. So you're left with a character that can't compete in this risk-based damage game.
BTW sorry to those like TiZ and others who are learning the game and don't want to read this kind of stuff. Leixia is a fun character to play and you can win with her. We're just talking about tier lists for tournaments, and I doubt you're going to see a Leixia winning any big tournaments, because she has too many weaknesses that a top player can exploit if they know the match-up. I'm not saying every match you play against anyone is an auto-loss, far from it.