imho mdma isn't too trippy and easy to handle without having experience with/an inclination for psychedelics. it has a certain visual component (mainly blurring, tracers and intensified colours), but doesn't lead to the thought processes typical for psychedelics. if you want to keep psychedelia at a minimum, use the lowest effective dose and don't redose.
that said, i have seen the insides of a dimly lit mobile toilet transform into a jungle landscape, but the dose wasn't exactly low and i had done lots of dmt at that time which surely had an influence. typically such intense visuals only occur with mda.
at higher doses of mdma you might mistake a person for someone else for a short amount of time or see glasses on all people (which is not at all typical for psychedelics), but you'll normally be too happy to get freaked out by that.
lots of the rcs get mixed reports with some people finding them more psychedelic and some less so. in general the apbs are more like mda in that respect, while methylone is more straight. but methylone is a "mdma light" of sorts with many essential parts (like the extra-intense body high, the love/empathy and the pleasant disorientation) missing.
endorphins indirectly at most. serotonin, noradrenalin and dopamine are the main neurotransmitters released. with serotonin and probably more importanly oxytocin (released indirectly through activation of serotonin receptors) being responsible for the social effects.