Reliability; Reliability; Reliability
As for conceal-ability, moderate to minimum concern. People have no clue what that bit of a bulge is in your pocket, or what is causing that little bump in your shirt above your belt. Besides, conceal-ability is as much a factor of style of carry, and holster as it is the gun itself
Accuracy, I seriously doubt that any concealable handgun made today would not exhibit accuracy sufficient for self defense. If you need it the target is not going to be a dot, and some surrounding rings on a piece of paper. It also is not going to be standing there stationary on a target hanger. It will be moving, bobbing, punching, grabbing, stabbing, etc.
Sights, at civilian SD distances you won't need much if any. If you take time to acquire a "sight picture", your family will have a nice picture of you on your coffin.
Quality, yes but that doesn't mean you have to spend the equivalent of a house payment to get it. Plenty of guns fulfill the requirements in the $200-$500 range.
Shoot-ability, that is totally subjective to the shooter.