You have a point about Gale. I'm not too fussed about his whole situation honestly.
How much people would recognize the armor and such is up in the air, granted. Your point about her romance is interesting too.
The issue with Lae'zel is that the writers didn't have to make her so vehemently single-minded. Suspension of disbelief is something I support, and I find the Lae'zel issue to be a more forgiveable example, but it just feels like an example of the writers prioritizing "coolness" over party/gameplay synergy.
And with Astarion, just because something is interesting doesn't mean it's actually good. The movie Cats is very interesting, but there is much debate about its goodness. I don't think it does a good job of introducing his character, or at least, it fails to really make him an appealing addition to the party. And when he's the only rogue available, a particularly important character archetype, that's not good.
