i'm planing to make PvP SG sniper so i need few tips. i was planing to go like this:

i have some questions:
do i need to tag outdoorsman skill?? i was reading some topics and i see its always recomended to tag, why??? can't i just normally raise it to like 80% and tag repair instead? or even first aid?
also, do i need to tag doctor? i see its recomended for pvp builds, why?
how hihg should i go with 2 secondary non combat skills and why?
should i pick lifegiver on lvl 12 insted of action boy? if i pick that i would have 148 hp at the end in stead of 108.
any suggestions are welcome.