Mastered this game a while ago, getting all (ranks, missions...) When starting i got 1 quest instantly (complete 7 missions), for the other 5 i have to do 2 runs again (1 in normal, 1 in endless) to get the other 5 quests... but thats rly not a problem, the 2 runs was done in roundabout 30 mins.
Took me just over an hour from scratch, not too bad. I couldn't even get close to 2000m for Run And Gun, then I got the 50% fire rate boost upgrade and bam, got it the next run. If there were more levels instead of just one long one and an endless mode I would play the crap out of this game, it is so fun .
looks like i having same problem as komodor - machinegunners can take everything, air strike including. Still i will try to pass 2000m quests with this...
Pretty much all of the squad members are useless except for Rocketeers and Marksmen (once you have the double shot).
Beat the boss without even getting full upgrades, and my very first attempt at endless I got 2000m easily. I don't think I lost a squad member except when I killed off the grenadier I picked up by accident.
Probably could have gone a LOT longer, but got bored.
The reduced damage perk and the 'invincibility when use special' perk are key.
Most funny thing happened today. In my first run in Endless mode enemy machinegunners were not invisible for about 1200-1500 metres. Then they become invisible again, but this headstart was enough for me to pull out 2000m trick.