Also, for the single-key abbrevs I'd not use any prefix at all just like I have in my browsers "g something" googles "something", it's close to never when I need to search for a single letter (and in those cases I'd just add a space before " g" to let it parse as a literal)
These ! prefixes are nice "visually", but the ergonomics haven't been thought through
Basically, customization is the solution to such design mistakes, but lack of customizatin is another design mistake :(