1. For the last several books I've seen nothing to slow down the Yeerk effort, or the Yeerks making any smart effort. They've done some things for finding the Animorphs or gaining technology (YPM, Pemalite ship), they've pushed political agendas (30), but they aren't making big steps in gaining controllers, so I can't really say that the Animorphs are making that big of a dent. I can still see wanting to get rid of them, and an Anti-Morphing Ray is a fairly good way to go about it, but there should be something else going on.
2. This would also be kinda cool. Few, but existent light receptors, extruding stomach. Hydro-skeleton, must have some sort of mind. This isn't one I've put a lot of thought into, can't see anything wrong with how it's shown in this book, but I would like to try it. Know for sure.
3. I found them both appalling. Both worthless on their own, if anything damaging. I do wonder about the division though, was short term memory and aggression random, or must they go together. Addressing Mean Rachel's growth was a good concept, but it would have seemed that this meant she would be checked from here. Nope. 5 books later she'll be worse than ever, and I think that was total lack of planning.
4. Also interesting. Much more complex than just wanting to fight. I'm sure a part of it is people she loves, but like some other people I know, Rachel comes off as an actual altruist. Without realizing the risk to herself, she protects to protect (that I think is apart of her thing with Tobias). She's not soft or very emotional about it, but she doesn't like people to hurt. Irony in how she goes about it of course, but that's the best explanation I have of it.
5. Fear and optimism vs pride and greed. The first would be faulty in fearing it's own shadow, a relectance to trust, and both helped and hurt by the dream of a better tomorrow. The second would be a bit of a sadist, manipulative and arrogant (I was going to say Voldemort, but Visser Three seems more appropriate.) I don't see the former fairing well (pessimism, ironic) the
latter might do okay, until it pissed off too many people by a lack of restraint. I think ultimately they'd reconcile, because the one would need to get past fear to function, and the other would be willing because it understands that to use people to the fullest, you can't just manipulate and underestimate. You need some restraint, and a touch of mistrust. Well, I's would anyway.
6. I'm ashamed to say when I first read, in the summer of 99, this is where I took my break. It was probably another year before I resumed at all, and more years till finished the series. It wasn't out and out dislike, but it was the 30-32 stretch were I felt the tone shift. The writing style was different, the characters monomorphic in ways that opposed all they'd done up till now, and so I just.... fell away. In 5th grade, two polar Rachel's seemed irrelevant enough that I stopped caring. And this was not a ghost written book.