As far as I know, crafting marksman, man at arm, or scoundrel skillbook is not possible.
Only 1 issue of barrage book is available in the game. If you did respec already, I fear the skill is no longer available for you.
Ranged power stance is buyable I think
homestead ice elemental or any marksman vendor?
Summon wolf is not an expert marksman skill but a geomancer one. The skillbook is not buyable and is hidden somewhere. The scroll is however buyable/craftable so it's easy to relearn the skill.