I'd really prefer for emacs' implementation language to have been a lisp-1 rather than a lisp-2. It's annoying to have to do different things to treat a function as a value (put it into a list, assign it to a variable, etc.), as opposed to all other kinds of data. Any benefit you get from allowing name collisions (i.e. function named f, related but distinct variable also named f) seems very small in all elisp code I've seen and promotes confusion more than it enables desirable programming patterns.

I'd make lexical scope the default and dynamic scope opt-in on a per-variable basis. This one is probably less controversial. I think the devs are moving in that direction (e.g. by changing emacs core code to use lexical scope and adding warnings for code that doesn't opt into it), but I don't see how they will actually be able to change the default without breaking a whole bunch of user code.