Re: Perfection of waza
There has been some good advice shared already and mine may not be as good as or any better than what you have already received so take it or leave it as you will.
I feel your Aikido technique will always be something you will be refining (or perfecting if you will) your entire life. My Sensei has been studying over 12 years now and he is constantly talking about something new he discovered by refining his technique or something new that he learned at a seminar we attended.
With that in mind you'll never progress past learning 1 technique because for the rest of your life you can refine and tweak little points of that 1 technique.
Perhaps if you could find a way to change the way you look at your training so that Aikido is not a "sheet of music to be learned and mastered". It is a journey you are taking and you are merely along for the ride to enjoy the scenery.
Don't know if that helps or even makes sense but it is just my take on it.