Does more than 4 drills in a weekend equal more pay? If so, is it proportional?

You get paid by the UTA (or Unit training assembly). There are 2 UTA's in a day - 4 in a weekend & 6 in a 3 day weekend.

Yes. You get paid the equivalent of one day's Active Duty pay for each UTA/drill. Multiply the number of drills/UTAs by the daily pay.

Each UTA SHOULD be a minimum of 4 and a maximum of 12 hours. You cannot have more than two drill periods in one calendar day.

Not when I served according to our CO , the entire weekend was considered a drill but we were normally dismissed after an 8-10 hour day. This was Texas ARNG 1970-76. I know I'm old.