Proper fingering to me seems extremely important, especially when you are just learning. You will develop good fingering skills easier, and they will stand you in good stead throughout your playing career. Even when you later "do your own thing" those skills are still at play. I can see now that it is so much easier to play altogether using proper fingering, and I wish that I had that training and those skills. I would say to a person just learning, bite the bullet and learn proper fingering. You will not regret it.
I have a Yamaha Motif XS keyboard. When I first got it, I was having serious finger and hand pain after playing it for long practice sessions. I have had and have other boards that did not cause this pain. I posted on motifator. com and received suggestions that my pain might have been caused by the mechanics of my playing. I took a real close look at my approach to my board and my fingerng, and noticed that my fingering was atrocious and I hadn't even noticed. I was stretching the middle finger of my right hand severely and barely using my ring finger at all(among other things). I made a conscious effort to correct my fingering, adjusted my seating in relation to the board raised the height of my stool, and the finger and hand pain ceased to be a problem. Why it wasn't a problem on Korg, casio, roland boards that I have/have had, I don't know.
Additionally, it it reinforced something that I already knew and had not really acted upon. It is much easier to play overall using proper fingering. Learning on my own, I had developed many bad habits and was reluctant to put in the time to change them. There is wisdom in the madness of learning proper fingering. The best time to gain those skills is when you start.
berbie