Never rely on "street names" or what the drug dealer tells you it is. It's 90% bullshit.

"Ecstasy" was originally used as a synonym for pure MDMA, before the crackdown on MDMA and its precursors. I have no idea how the term is used these days.

No. MDMA is itself a stimulant. "Ecstasy" and "molly" are synonyms.