when you select a word using Ctrl+Shift + left/right cursor the selection should stop before not alphanumeric characters (eg: , . " ' ...)

at the moment it stops after . and not stops properly before " and '

meanining of Ctrl+Shift + left/right arrow combination is different. It moves cursor to the next (previous) word start and selects the text while moving.

I think this meaning is quite different from other editors, not?
why don't you add the fact that the cursor move to the current (previous) word end (beginning) before going to the next (previous) word start?
you could add this as an option, what do you think?