Haven’t tried it, but you could use a smartphone + Corne Choc + trackpoint

It’s wired. There are versions with Bluetooth but no trackpoint.

It fits in a external hard disk case

In zero time: no one. Emacs gives you all the ingredients to make an IDE, but you can’t bake a cake in zero time. It will take time (and be gradual, just like leavening).

Can’t give you exhaustive reply right now but I suggest to try fit your editor to one language at a time: start with Emacs Lisp, then maybe Python then something else…

Make Emacs fit your needs NOW, or you’ll get overwhelmed.