Highest is not defined.
and I can't quickly change grid's divisons
Is that what you want? I mean typing numeric input is the fastest way to go most of the time and may has that built in tool or not tool.
Anyway there's really no reason why you couldn't make grid change a hotkey/button/dialof of some kind. Its just a question of what kind of work flow you need supported. This said if we knew your workflow it would easier to fix what your doing badly at the monet than fix the result of such things.
"Discrete" option for tools is buggy (to me)
Dont blame things on bugs even if there are ones, its unproductive. Thing is its like blaming other people for problems, at the end of the day nothing changes until you tackle the problem. So yu really need to define buggy better, to yourself at least so you can build a work flow that works for you.
Now since this is a work flow question really what we need to know is what your work flow is so that we can give you any meaningful input. If on the other hand you just want confirmation that things suck then lets quit here shall we (im not saying you are but about 10% of posters really are looking for this answer, they can not be helped)