More être verbs than DR MRS VANDERTRAMPP?
The être verbs list seems to exclude "se promener", whose auxiliary verb is not "avoir". (There may be others not included, but I only noticed this one) Is there a reason for this not being included on the Vandertrampp list, and which other verbs should be included?
NOTE: I could just as well be misunderstanding this concept of être / auxiliary verbs; please explain if so :)
se promener isn't included within the DR MRS VANDERTRAMP(P) because it already fits snugly within another category: all reflexive and reciprocal verbs use être as their auxiliary verb in the passé composé. There is no exception to this that I'm aware of.
Also, just as a note about the DR MRS VANDERTRAMP(P) verbs - many of those verbs have additional meanings which don't use être as their auxiliary verb, and just use avoir instead. For example, descendre can mean "to go down", in which case it takes être (e.g. Il est descendu avec les valises "He came downstairs with the luggage"), but it can also mean "to take down", in which case it takes avoir (e.g. Il a descendu les valises "He took the luggage downstairs"). Have fun!
And to make things more complex, 'descendre' with the meaning of 'go down' exceptionally uses the auxiliary 'avoir' in a famous children's song, 'Gentil coqueliquot': 'J'ai descendu dans mon jardin | Pour y cueillir du romarin.' This is possibly due to regional usage.