Many of the symptoms you mention sound like they could be something like thoracic outlet syndrome (TOS) or a combo of the c spine & TOS.
You may want to explore our TOS forum for more info on it.
http://neurotalk.psychcentral.com/forum24.html

a previous whiplash type injury + a repetitive job can set you up for TOS.
Flare ups after usage is a symptom for TOS