it completely depends on context and interpretation. there isn't one correct way to play an accent, and you are correct that it doesn't explicitly mean to play louder. what you're describing as an accent is kind of like a fortepiano. similarly, what i described as an accent closely aligns with a sfortzando. point is, accents are vague and there isn't a correct way to play one. more specific styles aren't necessarily correct, and an interpretation is generally only made unambiguous with notation like the aforementioned fortepianos and sfortzandos
correct, but the part shown here is for a transposing instrument. it sounds a fifth lower than it is written. so though it is written as A and E, in concert pitch, these notes are actually D and A