I think that while she is hyper competent for the most part it is explainable by her upbringing on Jakku. She learned to speak a variety of languages due to the mixed nature of the scavengers. Her fighting ability is self explanatory due to the rough nature of the locals. She learned how to repair, maintain, and fly ships as those would be essential skills when doing scavenging runs and odd jobs.Zontar said:She had a fairly good attitude, but it's hard to take seriously when she's hyper-competent and has instant mastery at things she has never done, but that's a discussion for another thread.
A lot of people say she is too good with the blaster but she really only hits 2-3 Stormtroopers who are caught by surprise, Finn and Han are far more competent than she is shown to be as far as shooting.
The force abilities actually comes down to a personal theory of mine. She only exhibits these abilities after the vision caused by grabbing Luke's lightsaber. My theory is that Luke imbued the lightsaber with the vision of Kylo's betrayal and some way to trigger an individual's personal memory to keep them from abandoning the quest. In Rey's case the knowledge that her parents left her and would not be coming back. Additionally he packed it with knowledge about the basic abilities a force user should know in order to give any new force user a jump start and a fighting chance against the Knights of Ren and the First Order.
Its only a personal theory but I feel it makes sense. Kylo is shown to force interrogate, the lightsaber knowledge bomb is pretty much the opposite of that.
She is still a Mary Sue and I hope she gets knocked down a peg in the next 2 movies, but I did actually enjoy her screentime.