Allen Payne should just walk around shirtless (sans taco chest hair, of course). I sincerely believe this will bring greater depth to the show.
Seriouly, I'm not sure if the problem could be solved with better writing. Allen Payne is not a good actor. He was better as "Lance" on the Cosby Show and that was how many years ago? His range hasn't improved since then?
I also believe the person playing the college-aged son should be removed. Horrible.
Maybe they should bring in Debbie Allen. She's a competent director and has a track record for saving a sinking sitcom ship (e.g. A Diff'rent World).