Longpool in p2pool is every 10 seconds (average).
I`m mining at avg 150MH/s and there are times that I not get any share over 24hrs and sometimes I get 5 of them. This is only luck

Your miner settings are ok, higher queue leads to more DOAs and more threads in that MH/s power is just useless.
Sometimes longpools can hit every second or so, but it is 30s sometimes too. Avg form last few is always 10s - this way p2pool share chain is regulated (shares are too frequent -> share diff goin up).