> - Squeak would provide some simple way to say "please instantiate these
> specific blocks as closures" (maybe this one exists?)

Sure, use an image with the new compiler (such as
http://www.iam.unibe.ch/~denker/temp/NewCompiler.zip). Then either
change the global settings or implement a method like

LazyWhatsoever class>>compilerClass
	^ ClosureCompiler

in your classes where you want closures.

Lukas

-- 
Lukas Renggli
http://www.lukas-renggli.ch