Just listened to NPR's interview with Pete Abrams on the 10th anniversary of Sluggy Freelance. The NPR host actually does a really good job at the start of describing the main characters. The links come from a recent post at FLEEN. The key "reveal" in the interview: his great grandmother on his mother's side was named Sluggy Freelance (yes he's kidding).
Two things to add: my understanding is that Pete makes the bulk of money now from his Defenders subscription (essentially a "patron" sort of model); and Pete has always remained a bit secluded from the rest of webcomics. He didn't link out much and other than participating in the very first Fright Night event I don't think he's really done "community" stuff. In part I'm sure it's because he never needed to (Sluggy was the Penny Arcade of its day back in the last century in terms of being much more popular than its nearest competitor.)