Question:

Is it 私は/携帯で自分の写真を撮るの/下手なんですよね。? Is 携帯で自分の写真を撮るの a noun phrase?

Answer:

Yes. It's grammatically OK.
Yes. that pahse is a noun phase.
の at the last makes that phase noun phase.
の is euivalent to 事　in this sentence.