getting stoned before rolling normally resulted in a long long comeup and then a short and mild roll. add alcohol to the mix and I would bet you would be even more dissappointed. If you are looking to get runk and high before you roll I would wait until you came down from both before taking you MDMA. you can drink on MDMA but drinking until you are plastered can cause blackouts. 1 or 2 drinks would be alright but anything more and you are going to see decreased effects from MDMA.
save the weed for the comedown or smoke it sparingly durring your roll...too much weed will cover the effects of the MDMA and you will just feel really high.
I find a moderate amount of weed is necessary to fully bring out the appreciation of colour from mdma, however too much and i just feel really lazy. A small amount of alcohol before often helps me start in a relaxed mood and makes the start of the experience better, although having not that much experience I cant say for sure it doesn't lessen my experience in some way.