Is Safety the most important aspect in the duties of an aircraft technician?

Safety is ONE of the most important aspects. It is pointless being "safe" if you don't have the knowledge and ability to correctly carry out technical work on an aircraft.Therefore I would suggest that  the first priority is that  you need to be able to "do" the job, first and foremost, if then you have that ability you should ensure that everything you do is done with "safety" in mind.

Thank you Peter, rightly said, of course without the required knowledge and skill, no one should be permitted to work on the aircraft. Moreover the technician must also know about known common mistakes and specified safety requirements to avoid any ground crew induced emergencies. It's always good to remind the concerned about these important aspects.

yes without any doubt

yes, its the first priority before any operation