I feel to prevent damage to structures the normal bullets should be replaced with bullets from FFS if this is at all possible, FFS bullets don't damage blocks but will remove whatever grows on top of them. Permission to use one of the guns resources from FFS should be asked for though.

Dispenser change: Instead of dispensing scrap metal and hypos, a change could be made so it heals people within a certain spherical range of where it's built, from NPC's to players.

The mini sentry should have a subtle change where it has the same rate of fire as a level 3 sentry, and, to compensate, a greatly reduced crafting time.

I believe also that these should substitute for the basic starbound turrets by being indestructable to everything but an enemy turret, or being uprooted from the ground by the ground below them being destroyed (BLU hurts and targets RED, RED hurts and targets BLU)

Once again this is a suggestion, and could see use in the new remake of this mod since this one's no longer gonna be updated, I saved this as a discussion to bookmark the possible changes, and the mod author has every right to take over in the comments section.