I'm really surprised that someone hasn't built a Smalltalk-like OO web tool that would build "dynamic web pages", using objects to assemble the screen dynamically with each request.


They have. Its called WebObjects. Use it once and most of the rest of the web app tool builders look like pikers. You can now use WO as part of your J2EE stack and deploy into existing app servers. So you can just use the presentation layer, or the OO/RDBMS mapping (which does in fact precalculate and prepare most statements it uses). Its only $700 but the tools only run (well) on Macs.

Or you can switch to Smalltalk or Ruby and use Seaside which associates single argument blocks with form elements to let you store the results coming in anyway you like. Both of these make the conventional templating systems look like freshman level projects.