"from the school of Anno, and Yuasa, style"

If you're talking about animation and art direction styles, Anno and Yuasa aren't Imaishi's influences. Imaishi's art influence comes from Yoshinori Kanada, who's known for his zany poses, exaggerated movements, giant lens glares, and lively looking light beams. He's one of the most influential animators to date and has an entire animation style named after him. Imaishi took the exaggeration to another level and really made it his own, but the influences are still obviously there. Imaishi is also pretty vocal about how much he likes Yoshinori Kanada's animation.

I'm surprised that you didn't bring up Re:Cutie Honey, Abenobashi Mahou Shoutengai (Magical Shopping Arcade Abenobashi), or Black Rock Shooter. Imaishi was heavily involved in Re:Cutie Honey -- he directed episode 1, which was the beginning of the Imaishi - Nakashima combo that later went on to do TTGL and Kill la Kill. He also did a lot of animation for the show. Imaishi was also the storyboard-and-animation director for episode 3 and 12 of Abenobashi Mahou Shoutengai.

Imaishi was also in charge of the CGI fight scenes on Black Rock Shooter. He pioneered the art of filming CGI at the same varied-frame rate as hand-drawn animation, which removed a lot of the awkward unnatural feel that people normally associate with CGI and added more impact to the action scenes. He also did some heavy pushing of CGI poses, movement, and camera angles, making CGI humans actually look dynamic and interesting.

Compared to those shows, he didn't really work on Fujiko Mine very much, besides the (admittedly awesome) pieces of animation.

Paying homage to Osamu Dezaki, Kunihiko Ikuhara, and the battle shounen/shoujo genre's

Kill la Kill is also heavily influenced by Cutie Honey. Just watch the first episode of Re:Cutie Honey (also directed by Imaishi) and you'll see what I mean.

very detailed, multi-layered metaphorical series

That's mostly Nakashima's writing. If you want to see Imaishi's writing, go watch Dead Leaves -- it's about as close to a pure Imaishi vision as you can get.

In the future of these write-ups, it might be helpful to separate out animation directing and story directing. Some directors like Yuasa is a blend of the two, but Imaishi is mostly an animator who has recently begun directing -- a lot of his contributions are visuals only.