Hotkeys in DE questions

Is it possible to change the hotkey for building a house to simply H, or Barracks to B?

This seems to then impact creating units as well because the hotkeys are formatted by Rows and Columns (which is by far the most frustrating hotkey system I've ever come across).

Any tips I'm missing?

Also is there a way to select all units on the screen without double clicking (e.g. holding CTRL and clicking one unit like in sc2)?