It depends on the team really.

for me,
if the team are pretty good in following objective, just do whatever they need most.
if > half of the team are not following objective, I join them be Recon sniper, fishing, train my sniping skill. lol.

I could ruin my K/D down to 0.3 by just following objective.

Your ultimate objective of playing the game is what fun u want to archive for that day that round. U can play shotgun that u are not experience, and just get 1-3 kill. Just make sure that what u do in-game, dont make fun/fool about other will do. things such as driving a fully teamate load of vehicle to suicide lol.

Thats a perfect example of a medic that Care.....sometimes it is best to camp behind ur teammate and keep reviving them, because if u die = they all die. I think Drbluebox is just doing that part of the job. Unlimited life teammate ftw.

if my teammate is good, I actually have my defiltrator on almost all the time.