You are getting some good advice.
Bane Lord ideally should be equipped with(and this is at constr 4, obviously better items exist down the research tree):
Weapon Fire Brand: This is a no brainer, aoe attack and fire resist
Shield-Charcoal shield or eyeshield are both good. Lucky coin is also good.
Body-something light weight to increase his movement, that also has high protection
in mail displacement or silver hauberk are both excellent.
Helm-Horror helm at const 4 is nice, obviously if you are going against a race with units immune to fear or a fire mage race, you want 100 percent fr over fear.
Boot-quickness are best, but that is const 6. Since you are there in your present game, stick with those. If you were cranking out a bane lord at constr 4, go with brimstone boots for the 100 fr and extra str.
Misc slots:how much mr do you really need? In a mp game when you are being mind hunted etc, it can never be TOO high. But In a sp game, I think you are fine with the luck pendant and ring regen.
A bane lord that is regenerating at 7 per turn is hard to kill with a smites, especially when they have only a 50 percent chance of landing.
But against a race like ctis, with their level 3 priests, or other races with high level priests, then the advice to forego offense for defense kicks in.
I would never discard luck or regen. you need them both in some form in my opinion. Maybe go with faithful weapon, lead shield, brimstone boots, horror helm, chain mail of displacement, and the ring of regeneration and the amulet of antimagic if you are facing a nation with tons of priests that smite.
The advantage of the charcoal shield, especially when combined with the horror helm, is you may be able to win even if paralyzed. Units that strike you take damage and are subject to fear effect of the helm and may rout.
So the long answer is, there is no one best answer. much depends on who you are fighting, and what types of damage and units they are using.