- The character I was most interested in (Lena) was no longer in the anime
Fair enough, I've seen quite a few people share this criticism. Tho keep in mind that not giving Lena any screen time is actually intentional cuz in cour 2 we are following the story of Shin's crew, and from their perspective they know nothing about Lena's fate. So not going back into San Magnolia helps creating tension.
- The action scenes felt pretty much more of the same, random images of generic robot-enemy firing missiles and not hitting anything, while Shino dodges everything and takes down the whole enemy generic robot army
Yeah, I can see why you would get bored of the fight scenes. Especially when you realise how many still frames they started reusing in cour 2 (my guess is because of production issues). Plus the fight scenes lacked most of the tension cuz I knew the squad (especially Shin) will somehow always make it out alive. Which brings us to the next point: