You ate all the chips is a pain to get. You blew it up is EASY just play invasion and play that map o_0. Offensive Drive was easy on the warhog racing mode, forgot what playlists (action sack maybe ? you'll just check on bungie.net which playlists have what)
Thou I would like the few I have left (got the drm kill few times yet not unlocked -.-) I personally will ever boost for anything like that. I earn achievements, not much point in them if people just stand there and let me get them (like thats what would
happen boosting the stockpile achievement.
Anyway, thats the only one you need to boost for (flags). The rocket race kill and the invasion ones are easy.