Do you have silver fillings? Taking any chelator while you still have silver fillings can be dangerous.
The effect of DMSA on yeast varies a lot from person-to-person. I (and some other people I know who have tried it) didn't have a lot of trouble with it, only very mild yeast reactions while using it. Other people have had more trouble.
I'm afraid that the only way to know for sure what effect it will have on you is to try it and see how your body reacts.