Forth (or PostScript, which I have written) has the problem that I never trained my brain to work in the stack-oriented way.

Smalltalk is nice, but its "all of the world is an image" approach really gets in the way sometimes.

I would like Lisp better if it had syntax.

It's probably worth at least exploring one of the languages in your theoretical list. I've done some Haskell programming and it's a good way to expand your mind, especially with pattern matching function signatures and currying -- even if you don't get into monads or continuations. The choices for syntax annoy me in some places though.