I'm getting quite anoyed with losing dwellers to not being able to target them while they are fighting mole rats or such.

Maybe implement a mechanics where using a stim pack in a room heals the lowesst HP dwekker or something?

Yes this is a must actually, I would have thought a sort option on the dweller list by health and the option to use a Stim pack while still on the list screen. Every dweller I have lost has been the result of not being able to select them in time, while having 50+ spare stim packs.

I realise you can sort by job but this often does not bring up people together and is not really any help once you get to 30+ people.

This kind of makes the experience become annoying very fast.