A likable enough movie that could have been so much better: Beginners

Mark (?) Mills's "Beginners" is a likable enough movie despite, in my view, some major flaws - almost the definition of a three-star (out of 5) movie: It helps, getting into it, to know that the movie is to some degree autobiographical - the story of a late-30s single guy whose father reveals to him, shortly after he's widowed, that he's gay and that, in his late years, he intends to (and does) lead an openly gay life, after a lifetime in the closet and in a loveless marriage. This is very rich material, and Mills handles it effectively, with warmth and humor - helped a lot by a terrific Christopher Plummer as the dad. This part of the movie feels like a documentary, especially with some good archival clips that convey changing mores and several flashbacks that show the 30ish guy, played well by Ewan Magregor, in his childhood with a very lonely, troubled mom - some of this reminds me of a few of the recent extraordinary documentaries about ordinary people, such as Dear Zachary or Capturing the Friedmans. All that said, the parallel plot - young man meets a girl and they engage in a romance that reeks of a thousand other indie films and that never seems engaging or even credible for a moment: roller skating through a deserted mall and a hotel corridor, spray-painting graffiti on massive billboards over LA, the cute meet (at a costume party where he's dressed as Freud), the pop psychology (her father burdened her with tales of loneliness), the improbable setup (she's an actor put up in a posh hotel - but we never see a moment of her work), and finally the cute re-connect (he shows up, surprise, at her nyc apartment but she's in LA) - all this like a dead weight on a movie that could have been so much better.