Lots of information for you to digest. Brief synopsis of what I have seen looking at the information. Cow tag will take at least 1 preference point to draw. Buck tag is also valid in unit 41 and 421, the hunt code is DM041xxR. xx = the season you choose. Looks like you will need a preference point there as well. Keep in mind that I looked at this info very briefly and the preference point info may not be correct. All my information is based on the assumption you are hunting with a rifle. The info for archery and muzzleloader is in the stats as well.
I can't give you an answer for that one. Depends on which part of the unit you are planning on hunting. Some parts are probably better in the second season and some areas would be better during the third season. Maybe someone else on the site could give you some pointers without giving out their secrets.. You could also try to call the DOW officer in the area.
What does "gauge" mean anyway? As used here gauge means the number of round lead balls the same diameter as the inside of the barrel (aka the bore) that it would take to weigh one pound. It takes 12 lead balls the same diameter as a 12 gauge barrel to weigh a pound. The smaller 20 gauge would require 20 balls of that barrel diameter. The larger bore 12 gauge would require 12 lead balls of the bore diameter to weigh one pound.
In general the number of pellets in a shotgun shell...