RE: fore arm pain ?
I had this a few years ago and it got so bad I had trouble with any exercise which required a palms up (or down when doing tricep push down)grip. Think it is something to do with straining the tendons. The first thing I did was switch grip to neutral on as many things as I could e.g. used closegrip attachment for pull downs, switched to the rope handle for cable curls and tricep push down, turned dumbells into hammer curl position too. I also switched to the EZ bar and have never used a straight bar, apart from bench/shoulder press for upper body since.
Once the pain eased I brought back barbell curls with the ez bar but for a tiny weight, lots of reps. After about 6 months everything recovered and have been able to curl heavy barbells (EZ), dumbells no probs. If it ever feels like it's coming back just lighten up and change grip again.