Middle tree does give a lot more survivability (fighting at a distance) until you can get some 100% melee damage weps and shields.
Law and Order are a real good start.
And you can Melee in the middle tree just as good as the Bloodshed.
But you're honestly going to do more damage with weps until your get a: Melee override + Damage Relic Melee Mod (or cooldown reduction so you can do last second invisible super crits more ofter) 100% or 200% melee wep (gun damage doesn't matter, just the % melee damage) Roid damage shield (but you need a way to stay alive without a shield so you're limited to Law+Order or putting points into heals until you feel like a ninja)
Bosses are touch in the bloodshed tree while you're solo. You just run away, stealth and come back. At max level you just 1 shot them so... yeah... there's that.
Apparently The Warden and Hawke went on to join Revan and The Exile in their fight against The True Sith. I expect Sheppard to join them soon- Cheator13