Things i like to have:

0. A reason to level up my dwellers. (Making the enemy harder as they level up like it currently is ends with me not leveling them up.)

1. Endurance rework (Endurance not affecting HP would be best, maybe a damage reduction effect, or just the current radiation resistance bonus)

2. dweller HP displayed

3. a guard room (with assigned guards patrolling the level like Mr. Handy)

4. a Mr. Handy repair option (maybe a room to create spare parts out of caps)

5. outfit rework (details below)

6. More people assignable to the vault door or a massive damage boost for the assigned dwellers (raiders get more HP to compensate, death claws don't)

7. Radio shouldn't affect death claw attack chance (make the radio attract harder raiders like Ceasars legion or Enclave in power armor and have them only appear if the radio is used)

8. add melee weapons (just move the current weapons up and fill the first slots with some swords and axes)

Outfit rework: Please match the clothes to their use. A Vault shouldn't look like costume party if fitted for maximum effectness. Radiation suits should be best used in reactor rooms. Military should be best for guards (by granting a HP bonus), wasteland gear for exploring, jumpsuit for nuka cola, formal wear for diners) And make power armor as useful as their rarity suggests (by granting an damage or HP bonus).

Also remove gender lock on clothes and add opposite gender visuals.