First time post. So be kind please.

Neighborhood home game. $40 buy in NL Blind at $1 and $2
My first question: Does the buy in in relation to the blind amounts seem a little askew. It seems to me that with those blinds the buy in should be in the neighborhood of $80-$100.
This coupled with a total maniac that plays with us that will routinely raise to $15 pre flop with any two cards. I will limp or raise 3x bb and and he will come back over the top for $15-20. He does this to everybody. I play good cards and try to wait for a time to trap this guy but after playing and not winning a hand or two I find myself down to about half of the buy in. Then it comes down to finding a hand and just moving in with it and hoping the maniac calls and doubles me up.
I would really appreciate any advice on how to better deal with a total maniac.
Also, any opinions on the buy in in relation to the blinds would be helpful.
Thanks in advance.