How are the on-foot missions? I always assumed you needed a fully upgraded suit and that combat was practically inevitable on those missions. Is that not true?
Exactly as
@SteveWW57 wrote, for Delivery, Donations - no combat at all (but Reputation is gained). For Retrieve from Crash Site and Restore Power scavengers are NUC-able from ship with Dumbfire missiles. Just no rush, before disembark it is worth to check Contacts for scavs reinforcement ship(s).
Restore Power are also very good for looting materials, after power is restored - settlement is actually yours, you can check every last locker for loot, since scavs are not arriving after power is up. And when you in PP those missions could be a good source of merits (i.e. after last update, that is 2340 (after -35% reinforcing penalty) from Princess, so Prismatic are pretty reachable.
EDIT: never shoot to scav's ship (it is Clean, not Wanted) and Settlement when power is up - otherwise fines/bounties will be gained.