My husband used to like 3-card poker, but always played blind, in that he would play every hand but would never look at his cards. If the dealer hit a cold streak he would make a couple of bucks once in a while because he played hands that anyone else would have folded, according to the Q-6-4 rule.
What did this type of playing do to his overall expected return?

See http://wizardofodds.com/threecardpoker. Scroll down to the Strategy section, specifically the last sentence of the last paragraph.

Thanks, I missed that when I read it the first time around.
Michael only talks in terms of equal wagers for ante and pair plus. Does anything change if the wagers are not equal?
Instead of betting one unit on the ante and pair plus and then one unit on play, bet 2 units on ante, 1 unit on pair plus, and then 2 units on play if you want to raise the hand.
If the dealer does not qualify and you don't have a pair or better, if you have only 1 unit on each of the spots it's a net push for the player (-1 on pair plus, push the play, +1 on the ante). But by betting 2 units on ante and play, when the dealer doesn't qualify you end up with a net +1 unit.