That was what I tried. Unfortunately, it had the problem I mentioned with not being able to capture object references except for container relationships. That was a deal-breaker for me.

I don't think the Perl frameworks I mentioned are any harder to learn than Zope for someone who knows Perl, but the lack of mod_perl would be a problem. One thing you might look into is using SpeedyCGI. I think it will give you the performance you need for these tools without the need for recompiling Apache. You would need to get the framework you chose to work under it, but anything that currently supports CGI would be fine (Mason, Apache::ASP). Some authors would probably be willing to port to SpeedyCGI if it would improve their chances of working on low-cost ISPs ("web hotels" as you referred to them).