when SIA says the problem is fixed, you can be assured that the problem is fixed and not by cable ties. They cannot afford to offend their Solitaire customers of which many are CEOs, leaders, influential people.
if you can fly SIA for work related, why do you dispute? Be thankful, some companies insist on lowest quote for business related travels.
in any case, if there is a mishap, you can be sure of a higher payout by SIA vis-a-vis other airlines - just think SQ006.
Off hand, only Qantas has a 'better' record i believe for an international airline.
SG has a headstart for maintaining A380 because SIA is the launch customer. Also, the number of A380 being flown around the world is not that large to warrant the significant investment in labor, infrastructure. I am sure Emirates have their maintenance, Air France too - since these are two major users.
Regionally, it makes sense for airlines to fly their planes here for maintenance since SIAEC gives them competitive rates. Moreover, maintenance of aircraft is different from car maintenance, not any OEM people can do the job. You need certified engineers to sign off the engines / planes.