Skip,
I think that everything you are doing is right on! It's exactly what I've done on my farm. When I bought it 4 years ago there were no deer on it over 3.5 yrs old and most of the deer bucks had poor genetics. The previous owners had shotgun hunted it hard and shot everything they saw. After 4 years of passing the genetically superior bucks and letting them get to 5.5 yrs old, I'm now harvesting the kind of bucks I always dreamed of. It's also my goal every year to take one really nice buck and 1 or 2 management bucks that don't have great potential. I will hunt these management bucks at 3 or 4 years old. The longer you wait to hunt them, the harder they are to kill.
The only thing I might try to do differently than you outlined is to harvest as many of the does as I could during the early season. 2 reasons. You will be killing your resident does at that point. In the late season, deer from miles away come live on my farm because they are safe and there is plenty of food. If I kill a doe in January, I can't be sure I'm killing a "resident" doe. The other reason for killing does early is that it will make the rut better. Bucks will have to work harder to find does. I'd rather have fewer does during the rut and have more competition between bucks. This should result in the bigger more mature bucks that you've been passing, doing a higher percentage of the breeding. This sounds really good, but it's difficult. I was only able to kill a couple of does on my place early this year and we ended up taking around 15 in the late season. My preference would have been to take them early, but it's very difficult to kill that many with a bow.
I like you, love the management aspect of owning a farm and want mine to be the best that it can be. if you do all the things you mentioned, you should have great results.