Heh, I've already succumbed to all three, but not in a bad way, I hope. I'm making modifications (3), but that's because the whole thing is really new and I'm still developing and refining things. Reader feedback, even feedback from "awful webcomic" forum threads, is helping out.
I'm already thinking about putting less emphasis on the "talkin' critters" and include other cast members and potential complications. But that's good modification. I need to do things to make the points that need to be made without succumbing so much to (1) -- defensive explanations.
The second point can be tricky. I've already posted a nude glamor shot of Beryl for a donation incentive (which has proven to be very popular) -- but in my mind, the shot has a reasonable backstory, which I should probably include early on in the comic. One of Beryl's friends talks her into trying out for Playboy, and so she goes in for a test shoot. She is rejected -- her boobs are too big, or her stomach isn't flat enough, or her face just doesn't "love" the camera, whatever -- in any case, she's actually relieved. But you know what happens, the photos resurface later, just in time to embarrass her when she's running for the school council or something.
Plus, I don't want to make Beryl a complete sad sack. A girl doesn't want to be an object, but she wants people to think she is sexy and desirable. There are times when she wants to show off, even if she winds up embarrassing herself. But like you say, the trick is not to let her character change and devolve into a cardboard bimbo.
To balance her out in that respect, I've decide that she's going to learn that her farm is adjacent to an infamous Texas brothel -- a whole house full of bimbos. This will provide a more essential conflict to highlight her body and character worries without making it seem so much like she's obsessed with herself.
This will also give me more female cast members to play with. Looking at the site, I'm seeing Big Boob Beryl, Big Boob Beryl, Big Boob Beryl, over and over again. That's going to get old real fast for everybody.