RE: Shoulders exercise?
Seated db press does not NEED a spotter. Handy, but not essential.
I stand about 1m in front of the bench, swing dbs together back, forwards, back, then up (like cheating really bad on a curl), then sit down
Not easy, but possible.
Military press is a VERY good exercise and needs no spotter ...
Raw dead Lift 320kg
Raw bench 171kg
Shirted bench 200kg
Amateur cage fighter @ 95 - 105kg