How I can unminimize windows from an application using a key combination?
I'm from the same boat;

the best native keyboard-only  I've found is


CTRL-DOWN-Arrow; (you enter app expose)
DOWN-arrow; (if there are any minimized windows, this'll put a cursor on one)
LEFT-arrow/RIGHT-arrow (to select from multiple minimized windows) or hold OPT if you want all of them restored.
RETURN




alternative step1: getting into app expose before you've alt-cmd'ed to an app:

with CMD still held down, (the task switcher is visible)
tap DOWN, or UP, or 1 (now in app expose)



The above shows only one app's minimized windows at a time; for selecting from any minimized window regardless of app, CTRL-F3 moves focus to the dock, and you can arrow left to get to the minimized list.

if your CTRL-F3 instead shows you the app-expose, try FN-CTRL-F3. (In my settings/keyboard, I've flagged "Use all F1, F2, etc. keys as standard function keys")



Some apps have specific alternatives; I use Terminal's CMD-window_number, which unminimizes and focuses that window.