1.) + and - should add/subtract a date (actually the real request is = and -, as you don't want to force a shift).
Just to confirm here, the + and - already increment and decrement the date. But you want the = and dash to do this without the shift. The +/- from the keypad already work which is what it appears most of our users actually use (on the medical side) as most of them are used to using 10 keys.
2.) For all the hot key navigation behaviors, using Month as the example: the first M should get me to the beginning of this month, the next M gets me to the beginning of last month, etc. So I can step by 4 months just by clicking M four times.
Sounds like a good idea.
2. Likely it would be nice if the key bindings were configurable. I imagine that other languages might want to use other keys and/or there is always the possibility that somebody needs something weird, like I like to use Quicken like bindings (m for beginning, h for end of month, y for beginning of year, r for end of year, etc.). I.e. there would a set of navigation actions (increment day, to start of month, to start of next month, to start of last month...etc) were the actual keyboard short cuts could be configured. Just a thought.
They already do have the ability to customize. These can be overridden for that very reason as there are properties already exposed that do this. Please confirm if I am missing something here. Thanks.