Hey, Roberto, I just got back in town...
At the moment I can only help you with item #4, as I've not dug deeply into 3.2 yet. Kriston of the AOLserver crew claims that 8.3 is slower the 7.6, but thus far my attempts to nail down why have resulted in the usual hand-waving partial answer that seems to be typical of him. My guess is that each .tcl page that's returned is compiled, rather than the page being compiled once and cached. This indeed would lead you to expect slower execution times. Supposedly 7.6 has more efficient threading (which was implemented by the AOLserver crew) but for lightly-loaded systems this shouldn't matter. Compile times will overwhelm anything else.
There's a thread in the AOLserver discussion forums on this, check and see if Kriston ever fully answered me when I asked the question if you want (I will myself when I catch up on e-mail, etc - my guess is that he hasn't).
