Hey..
You can use it 4-6 MAX times a year like mdma.. MDA is more psycadelic than MDMA. I didnt notice a drop in the loved up felling like some users describe and it lasts a little longer then MDMA..
I tried once in a form of pink powder, and its the most crazy eyes open trip..
About the second question, im not the most apropriate person to awsner, but i think you should avoid it using MDA..
Take care :D