Without a doubt the below named forum is the best source for information concerning terminal ballistics. "Terminal Ballistics Forum". I can't remember if you have to sign up for membership just to read the posts ---- but if you do it is well worth the effort. Testing is always ongoing on the various bullets that are made available to us. Dr. Roberts [ DOC GKR ] is a world renoun ballistics expert and runs this section for the "Tactical Forums". He lists all the famous brand name ammo along with their performance results. Remember you are looking for a minimum of 12" of penetration for the round to be considered a top performer. This distance takes into account any side angle shots you may have to take on the target.
http://www.tacticalforums.com/
To answer "some" of your questions outright --
500 rounds without failures, is the generally accepted round count for trusting a weapon for self defense useage. Many will shoot for higher numbers if they carry CCW and depend on their weapon as part of a job -- say 1,000 rounds is not unreasonable. A single pistol course can have the shooter burn a 1,000 rounds in one day ! My students will use, on average, 200 rounds every 40 minutes of range practice time shooting their "drills".
Practicing with the same ammo you will fight with is highly recommended and should be part of every range visit -- if you are serious about being "good" when the stress levels are through the roof.
Stress on the practice range is your friend.........and you should seek to add it whenever possible. Some simple ways to do this is entering structured competitions, shoot while being observed by friends or family, and placing time limits on a routine to stretch your abilities. Practicing next to a guy shooting a .44 magnum on an indoor range. You won't believe how distracting that can be while practicing your shooting drills.
I know using the self defense ammo can get expensive -- but some things have a price that you just can't avoid. One note: Using Blazer ammo [ AL ] with gold dot bullets can reduce some of the cost --- CCI loads these aluminum cased rounds pretty hot, so for practicing it is great.
Hope this gets the discussion started............
JF.