In my experience with my own seeded lawn, I have had success with a mixture of fertilizer and a watering on a normal schedule to help it fill in bare spots. As far as fertilizers go, I had great success last summer using a greens grade Lebanonturf product. I believe it was the country club 18-4-12. It is greens grade and will burn your turf if not watered in thoroughly. by far the best fert. I've used to date (1.5 years) to help thicken up turf. It is rather expensive and not easy to find though. other things I have used are your normal lesco 21-0-0...as well as stuff with some potash and potassium in it as we'll. organically, I have been very happy with alfalfa. alfalfa will probably be the way I go in the future after I am happy with the establishment of my lawn. It's cheap in my area and helps to put nutrients into my awful soil.

basically patients, healthy schedule of watering, mowing (2/wk) and feeding as well as a good weed defense program is your best bet. Seed takes time, but it will get there.

Check out the Bermuda bible if u haven't already.

If I were you, I would rip out the common and sod it. You will be much happier with the hybrid bermuda. I agree with harvey. A reel mower will help lots.