Just very basic on your Marked Man: I'd recommend that not all of the lower-ranked players stick together; I've seen a cascading Marked Man effect where two-three players on a team will be grouped together protecting the Marked Man, and when he dies, it switches to one of the players who was guarding him - he can quickly die as well, and perhaps even the third. I've been winning a MM round 4-2 and suddenly losing 4-5 because of that exact effect.
Otherwise a great post: I have a feeling in the back of my head that MOST objective rounds are 3 minutes total - since the game can only run 6? rounds total, that would put it at 18. If you're sure on Chain Reaction being 5 (and I think King of the Hill is as well at the beginning of the game), then the other five possible rounds would add up to 15 minutes and 15+5 = 20 total. Can't say I've been in a match longer than 15 minutes but I'm not positive!
Team Objective is the only mode where I find "Carpet bomb" useful.
When the enemy is clustered in a zone or on the Hill, running in and dumping the bombs or throwing in from a short distance can thrash entire sets of people. And at 7 medals, or 5 with bargain, it's a cheap way to clear out a room and easily replicable.
Thanks for the input all. I'll update soon.
This guide is actually surprising from someone who was against removing stats from Objectives. Well done though, you're on the right track!
I still think kills should count as personal objective points - but that's another discussion.