THINKIN RUT,
We have been managing a property in southern Iowa under QDM guidelines since 1996. Therefore, my responses to your deer management questions are based on the successes (and failures) we have had on this property.
(1) In my opinion, any adult doe (2.5 years old or older) is a good candidate for harvest. In fact, if we are able to determine a fawn or yearling doe is not a buck fawn, we will also harvest from these two age classes as well. Our objective is first to reduce the density and second, to balance the adult sex ratio. The age of harvested does is not relevant to either of these two objectives. In fact, if we tried to limit ourselves to one specific age class, we would never achieve the desired antlerless harvest and would fail to reach these objectives.
(2) We try every year to fill everyone's tag with a doe. Our objective is to harvest as many does as we are legally able to harvest.
(3) We allow the harvest of spike-antlered bucks regardless of age and the harvest of bucks 3.5 years old and older with 7 or less TOTAL antler points. However, in Iowa the last management consideration to worry about is genetics and culling. Iowa's wonderfully fortunate deer herd lives in a virtual year-round food plot. Therefore, nearly any Iowa buck will turn into what 99% of hunters would consider to be a trophy if that buck is simply allowed to reach maturity (5.5 years old or older).
(4) We manage a fairly large tract of land by Iowa standards (3,400 acres). However, it is possible to achieve great successes on much smaller properties, especially if you can get together with your neighbors to form QDM cooperatives where everyone is managing under the same guidelines.
I have written an article that appears in the current issue of Quality Whitetails (the QDMA's quarterly journal) that you may be interested in reading - it describes our management program on the property I mentioned above.
Best of luck with your management program!
OrionWhitetails