To report back how it went with raspberry pi, current and loading modules. First, I made rc.d file to check out if loading modules might work. And it did. With loaded pf module, I parsed pf.conf using safe net (sleep 400; pfctl -d). Since I was pleased with output, I used pf=YES in rc.conf and got pf up and ready to serve. This a bit complicated method is for a reason I was not quite sure about old pf syntax, just as I'm not if npf rules would be correct. Thanks all for help and best regards
Zoran