I don't think you should let your height hinder you. In some ways it might be more difficult to do certain climbs and in other cases it might be easier. Everyone has there own strengths and weaknesses. But the climbers with the most success (in my experience) are the ones with the best attitude towards climbing. Who always believe that things are possible, despite their weaknesses. Climbing, like so many other sports, is very mental. Stay positive and keep an open mind. This will help you achieve your goal of 5.12.
I know many climbers who can't do chinups yet can climb very strong (V6, 5.12). They really on their other strengths to send climbs. Technique is a big one. It's faster to get smarter than get stronger.
You may are may not agree with me. but i hope this helps you out.
