i think you are doing a wonderful job too! and you are certainly giving him plenty of socialising opportunities.

my 13mth old son also likes to watch kids, he is fascinated by them, particularly older kids that run around a lot and scream! so sometimes, i take him to a playground (even though he cant use much of the equipment), or to an indoor play centre, or to the pool to have a swim and he watches other kids there. he loves it! he's not directly interacting with them, but just watching.

just a thought!