I would go with your first diagnosis of: Ineffective peripheral tissue perfusion r/t compromised blood flow secondary to congestive heart failure, chronic obstructive pulmonary disease, and thromboangiitis obliterans manifested by lower extremity edema, cool hands and feet, and diminished peripheral pulses.
However, that one seems a little lengthy to me with the secondary to list. I think I would just go with CHF and thromboangiitis obliterans.
As far as interventions: TEDS for edema, teach low salt diet to prevent further water retention, his legs should be kept elevated.
I would think he would want to do ROM exercises to promote circulation (passively or otherwise), stopping of course if the patient experiences any pain. The only time I would think not to do exercises would be if the patient had orthopedic surgery in which the joint needs to stay aligned. That's my thought as a fellow student anyways. Good luck.