Hi,
First the general question, what kind of action is activating a solo mode ability?
Then on to some specifics, only looking at the abilities that will directly effect my players.
Feat of Strength :: Does this add to melee damage as well? If so can a player activate it between hitting and damage?
Blood Frenzy :: Can this ability be activated after making a failed roll to reroll it?
Stoic defense :: Effectively 5 free wounds for every combat? Can it be activated in response to taking damage? What is a 'Chosen Location'? Since movement speed is halved which is the goal moving slowly or staying in a certain area?
Wolf Sense :: Can a space wolf after failing a roll remove his helmet and then reroll?
Thanks,
Baz