Bone Pirate is worse than Hulking Draugr unless you've got sustain issues. You lose out on a lot of max stam & weapon damage.
Also, I know Bone Pirate was bugged a while back where the extra stam from having a drink buff active didn't actually improve your damage. Not sure if that ever got fixed.
Usually I run Molag Kena 2pc, Eternal Hunt 5pc, and Impregnable 5pc with full well-fitted trait. I like Molag Kena because I can time my burst rather than relying and waiting on a proc set. With 1.9k stam regen in BGs and using Leeching Strikes, I hardly notice the 20% increased cost in abilities. With this I reach a nice, if I recall correctly, 11.6k Surprise Attack tooltip and an 18k Incapacitating Strike tooltip.
However, have noticed that, at least in deathmatch mode BGs, my damage is just fine when using a setup like: Bloodspawn 2pc, Fortified Brass 5pc, and Impregnable 5pc with full well-fitted trait. I tend to use that setup when cloak is being countered too heavily. And just in case you're wondering: Very rarely will I get third place when playing with either setup, and that's with a high MMR. Also not a ganker of any sort.
But onto your suggestions: I never liked Clever Alchemist because you're out of a 5pc when your pots are on cooldown, which is 30 whole seconds of not being able to use the set bonus when there are opportunities to do so. Then there's heavy armor in general, which I've had no success with. NBs don't have any particular defenses that compliment heavy armor like the other classes(stamina based I mean). Sorcs have hurricane/dark deal, DKs have major mending/battle roar, and templars have a house/purge/minor mending. Cloak and fear are pretty much all they have, which are both situational. Lastly, DoT builds are definitely strong. It's just that when you run into a templar all those sets will be almost useless against purge spam.
This is just my take on the topic. My set choices stem from wanting to have builds that work well against each class because I don't like to have situational offenses/defenses.