As I do know something about banding sorry to say but holding a degree does not entitle you a band 6, absolutely nothing to do with it if you get the numbers elsewhere on the system. (the other half does not hold a degree and has no intention of getting it and sits on a band 6). This is due to freedom to act and responsibility.

As for the band 3/4 working on a vent (with supervision) NO!!!
Sounds like you are in with the bean counters. Band 6 minimum for specialist medical equipment. Band 5 for PPM and repair on lesser equipment.
Band 4 for a trainee.

Lets push this trade forward not backwards you cheapskates. Pay peanuts get monkeys.

Why dont you have a look around at how much things cost on an hourly basis (just had a bill this morning with labour costing £125 an hour)