Yes you need to do all systems in all the cases
You will have time for that
At least the lungs and CVS
Remember it's a show business just put your stethoscope on the chest a listen for few seconds
Patient with joint pain could be having rheumatic fever and murmurs or SLE with some cardiac involvement ...etc
It depends on the case perhaps the patient tells you that he/she are hypertensive also ...
So examination should be focused on the chief complaint but at the same time the more other systems you do the more points will be ticked by the patient for you