Finally I came up with a creative solution. I wanted to bring her out without risking her doing something crazy or hiding under furniture. So I got her leash and let her walk around. After doing that in the living room for a bit, I took her to the bedroom. I set up a chair next to the bed, so instead of making a big jump, she can make two small jumps. She figured this out right away. And after watching her do this a few times, I took the leash off.
I'm going to just let her sleep in the bedroom with me tonight, with all the doors closed but her litter box and food available. She's bound to be happier in a familiar, comfortable environment than in that little bathroom, which is all tiled and kind of cold. I'll pull out my suitcase and make a "nest" for her so she can sleep nearer the floor if she wants.
Meanwhile aside from licking her wound clean and having a shaved belly, she seems pretty well normal. She's not shaking, flinching, or making any more growls or anything, and she's being playful and affectionate.
EDIT: Just got on IM with Storm, who ought to know all there is to know about cats (has 9 now, has probably had 30 overall), she SHE says not to fuss over it, kitty'll be fine and they hop all over the place and don't rip themselves apart. She had her female kitten done last month and she was immediately back to normal. Luckie is here on my lap now watching the cursor go across the screen. He he.
EDIT 2: And for a cat whose appetite was predicted to be "reduced," she sure is hungry. She just grabbed a piece of pita bread out of my mouth b/c she wanted the mayo. LOL. She just cleaned out her foodbowl of the little bit of food I put in there.
EDIT 3: Now (midnight) she's sitting on my leg cleaning her tummy and shaved area, but she's very relaxed and just seems to want to be with me.