This seems very complicated, and confusing. Unless your code is heavily math-oriented, it doesn't seem like a win. Even in that case, you would lose the ability to easily move and factor subexpressions, one of the things I prize most in Lisp.
I also foresee problems with code that looks like infix but doesn't actually have the operator precedence rules of infix, especially with the interaction between (1) and (2). We really don't need to lose more spaceships. ;)
