Challenges
I prefer with a minimum setting for Timeout/Timebank of 3/7 days.
Longer if you prefer.

Skulls
It depends on the Game/Opponent.
To be safe send me a message to arrange more time and I will accommodate you within reason.
Otherwise your skull will most likely be added to my pile.

Email Reminders
I rarely if ever send.

Move Frequency
With only a few games active I usually move at least once every day.
With a higher game count I choose a few games to move in each day depending on timeout.