Hand #1: You mentioned you were short stack but did not mention by how much.
When you go AI with AK with 5 players in one of two thinks will usually happen:
1. You will pick up the blinds
2. You will get called by a pocket pair, Ak and rarely AQ or lower.
So most of the time you will go to a coinflip or worse (AA, KK)

I would rather throw in a 3bb-4bb raise and hope to get called by a weaker hand, if someone reraises me I will call.

Hand#2: No way I will fold AKo preflop on headsup. You are most likely ahead.

Welcome to the forum, I am sure you will get tons of good information here.

5 Sngs are a very small sample but it sounds you are on the right course