As you probably already know, a balanced Vegan diet is a challenge but it also has it's rewards.
With a bit of research and work it can be made to work quite well for certain people.
A good thing is to work closely with a nutricionist and have them use a program such as the
"Food Processor" to make sure you are not missing any important nutrients.
-B12: You are already probably taking B12 as a supplement but in my experience adding a micro-organism based source seems to work better.
Kombucha, Brewer's yeast, Kimchee & sour Kraut come to mind...there are not as high as the pills but vegans who take at least a bit seem to better than those taking just supplements.
-Lysine: Beans are the only plant-based food that provides a form of amino acid, lysine. Lysine is essential to creating protein, which fuels energy and muscle growth. Depending on your makeup, you might not be able to digest beans very well; look at Joseph D'Adamo's work ( I don't agree with it 100% but many of his ideas are very valid). If that's the case I say, supplement Lysine.
-Food combining for obtaining a more complete amino-acid profile.

A good source of ideas for nutrient rich Vegan dishes is the Indian diet. I was trying to create a mineral-balanced vegan diet with the "Food Processor" and it kept coming low in Iron & Copper. If I started adding Fe &Cu rich foods then the calories got unbalanced...the solution? Indian Food. The small amounts of spices on it contain a well balanced mineral profile...I was very impressed. It's like taking your supplements with your food. I am sure other ancient/ethnic cuisines that are traditionally vegetarian can provide other solutions too. Watch out for those that did consume plenty of dairy tough, they might not be as useful.

Those are just a few pointers, books have been written about the subject. However, sometimes it's hard to separate fact from fiction and what works for some might not work for others...keep experimenting, monitor your health, be aware that you needs (specially as an athlete) are unique and report back your findings so we can learn too...

PS. Unprocessed Soy is difficult to digest and toxic/estrogenic in large quantities. Some people do very poorly with lentils because they have low amounts of the digestive enzymes required to utilize them. The key is to find out if you are able to digest these foods and even then is a good idea not to rely on a single type of bean as a protein source. Diversify your diet.
I believe that in Asia they also supplement with seaweed...soy products can sequester Iodine so that is probably a way to counteract this effect...anyone?
Quinoa: it looks great on paper, it's what my ancestors used to eat BUT it gives me horrible stomach pain & bloats. Again, anyone experiences with Quinoa?