Gosh, that’s a lot of landmines! As others have said, you can “encourage” raiders to step on them by putting concrete underneath them so they’re more likely to path towards them. You could probably do the same with wood fences to give them the idea of having cover where they might want to try and shoot you, but no, it’s just another landmine.

Grab that stray unstable power core, those things are excellent for setting up isolated micro-grids for things like ambrosia greenhouses and deep drill stations. Or just add to your main grid.

You can get rid of your bedroom corners on the inside of your insulation corridor and move heaters and lamps into the space to save on movement costs.

Is the fence there to keep animals out of your minefield? If so, you could replace the sandbags with barricades and get rid of it, because barricades do that job too. And can be upgraded to plasteel as the game goes on.

Shelves to either side of your workbenches’ sitting spots loaded up with the most commonly used ingredients saves a lot of hauling time, especially for things like meals and drugs.

I’d maybe think about moving the hospital closer to the psychic emanator. Rooms don’t get quite as much advantage with it, and it really shines after a raid when half your colony is in the medbay.

All in all, though, it’s a pretty solid looking colony. Good job.