Can a RN do PT exercises

Why would they? I don't know about you, but as an RN, I would not feel at all comfortable with gauging a patient's ability to perform X, Y or Z physical activities. That is not within my scope of practice, nor within my comfort level, given my lack of training as a physical therapist.

"I know a RN can do ROM exercises and varying other basic stuff, but can they do any major interventions comparable to a PT ?"

Keep in mind that an RN would never be doing "ROM and varying other basic stuff" without an order from PT/OT. Please tell us that this is true for you also.

I have extensive training as an athletic trainer. I'm also an RN. I have (and have used) many PT and OT skills... but I've only used them on those very specific people that I was authorized do, namely "my" athletes. In my RN role, I wouldn't institute PT/OT exercises (even if I knew how to properly evaluate for their use) without an order for those services and clearance by the therapist because of their very specific and specialized knowledge and experience.

I have wondered myself sometimes when PT gets the patient OOB to the chair. Sometimes this requires the PT assistant as well and maximum assistance from both.

Sometimes I ask "are you going to return to help them back to bed?". Of course not, the 100lb nurse untrained in PT will have to figure it out for herself. And round up plenty of help.

No ! NEVER w/o an order. Big no no.

No way. I am no more qualified to practice PT than they are to practice nursing.