The problem with beans is that they are quite starchy. Not as bad as, say, a potato perhaps, but still enough so that they’ll impede your progress. The general consensus on the forum is that soy is also something best avoided, as are nuts/seeds, and grains (buckwheat, millet, etc.) are test items and should be eaten somewhat sparingly, making being a vegetarian on this diet quite difficult. The kefir/yogurt should help, though.
One thing you could do if you have the patience is to try the diet for a while with beans and see if you experience die off and symptom reduction. It might be that while the beans slow your progress, they won’t prevent it entirely. The only problem with this is that it can take several weeks for your symptoms to get better even if you follow the diet strictly, so you might have to run this test for a while.
Able900, one the more knowledgeable members on the forum, often says that the protocol and acceptable foods list are suggestions, and ultimately you’re the one deciding what to eat and what vitamins to take. Unfortunately candida doesn’t clear up overnight (I’ve been hearing 6-18 months… I’ve been at it for 4 months, myself), so you’ll need to be able to pace yourself. If I were in your shoes, I might try introducing buckwheat, millet, and kefir shortly after finishing the cleanse (not all at once, if possible!) and avoid beans instead, as a dietary compromise. I also imagine that nuts and seeds (which are not recommended because of mold concerns) would slow your progress less than beans would. But as long as you’re seeing progress on your candida overgrowth, I personally think it’s better to fudge a little here and there if it’ll keep you on the wagon.