You are the last person I ever want to correct around here, but.... it's the . (period) / , (comma) keys for cycling through the Basic adjustments. This is very handy; thanks for pointing it out.
As for adjustment size, pressing Shift does make the increments larger, but pressing Alt (on PC) is for Resetting the Tone and Presence sliders. Using the +/- keys work as expected, but the Up and Down arrows don't always move the sliders.