Not really. Racism, iirc, is defined as discrimination and/or antagonism against a race/races, so I don’t think demographic grouping counts.
Exactly. If one were to survey approval ratings from those aged 18-24, that wouldn’t be ageist.
If the purpose of asking was in order to make up a way to rope that age group into some sort of “plan”? Then I’d say it probably would have a flavor of ageism going for it.