While OotV+BB is a nice combo in that it provides un-protable damage and healing to the frontline, I'd still say that OoP+DF is a better combo for allowing the same frontliners to spam SY. Whatever healing they get from OotV is more than compensated by the +100 armor to the entire party. Not to mention the additional damage from AS and possibly BuH.
Given that those very same frontliners are your SY spammers, I have to go with OoP+DF because it simply outclasses OotV+BB in physway.
There's no reason not to take Blood Bond with OoP+DF.
DF is generally a waste unless you're warrior heavy.
Order of the Vampire sees its most use in teams like this: http://pvx.wikia.com/wiki/Build:Team_-_UW_Physway
To run it effectively you must have a +20% enchanting weapon and a Half Skill Recharge mod on it. Usually this would be done with a spear and a focus item.
Your best use of this skill would likely be to bench it for a while until you can get into more organized endgame activities which involve all (or nearly all) human players. You could still run it taking 3-5 physical damage dealing heroes and henchmen, but it is generally recommended that a solo player with a team of H/H focus on dealing damage instead of a support role. This is because players are, in general, more effective at dealing damage than heroes and far better than henchmen. Players have many PvE only skills that enhance their damage, often better gear, and always a better sense of priority.
If you want to run it with H/H's anyways, because no one can really tell you you can't, then get the correct gear and take as many physical damage dealers only as you can (after bringing healing ofc). Generally melee damage will be physical, but make sure they do not have elemental weapon mods or skills which change their damage type to something else.
I use order on my necro and it works very well.
N/Rt OotV,life,recovery,mend body,blind was mingson or protective was kaloai,spirit light or spirit transfer,+2 optional skills.