Great post, it's always nice to wear another hat once in a while.
Q1: C-Everyone who flies that much knows the rules and the 100K flier new when he purchased it that it was not upgradeable. The 50K fliers is a loyal customer and has the upgradeable fare, it's a no-brainer for him.
Skipping Q2 for now.
Q3: B-Mr 100K flier again knows the rules but is being insistent that they shouldn't apply to him. As a 100K flier I always take exception when high status fliers can't seem to get enough of how important they are. C should only be an option if Mr Self-Important insists on it.
Q4: B-He is a 50K flier who is unhappy that he can't upgrade further out from his departure date and that chances are the 100K's will get the upgrades. Subverting the system seems to be the best way around this. I've been at the counter twice now when this particular tactic was denied. It was beautiful to hear "I'm sorry sir but your record indicates that you upgraded with a confirmable North American upgrade. I will need to see that certificate"...."but I don't have that one with me"...."I will have to assign you a coach seat and put you on the waitlist, you're currently 8th"
Back to Q2: A-This question went back and forth on United board and it was clearly divided between singles and married/attached fliers. I for one am married and I see this as one of the best benefits, I strongly disagree with the mixed policy of stripping the shared status on the Departure Management list. Most married 100K's get to that level to the detriment of their spouse/significant other. Lots of nights away and such. My wife should be able to reap the rewards of my dedication to airlines and the status I've earned. I have never begrudged being in coach while a couple gets the upgrade. Now employees getting my FC seat is another matter.