Well if you are looking to target the WinCE platform specifically you don't have many other non-.NET choices. Well none, that I know of really.

As for large exe sizes, thats a Lazarus/LCL issue. FPC on it's own doesn't have this problem.

I did a quick google and found this though: http://dn.codegear.com/article/33066

I also did a google to try to find more accurate information about doing WinCE in Lazarus, I found this: http://wiki.lazarus.freepascal.org/Windows_CE_Interface

The only other option that I know of would be Chrome, which is definitely .NET. To do RAD you'll need to have a purchased copy of Visual Studio as it works like a plug-in for the IDE. But it's still possible with the free command line version! See http://www.remobjects.com/chrome/ if you're interested in that option.