From my experience (in actually casting BB on a divine and using it with both an impulse item and without), this doesn't look like it actually works. Which is why Superior Laceration Lore exists. This was true as of about 3 months ago so before advising that add on I'd suggest actually checking it. Wasting a level for a metamagic you don't really need to further dilute the potency of your build (you lose a level 9 spell for basically no reason) just seems like unsound advice. If something has changed that now lets force bonuses affect BB again (because clearly they did work before), I haven't heard about it.1 extra metamagic; Force I enh (+40 Spellpower to Blade Barrier and I think Cometfall); lvl 1 arcane spells like Expeditious Retreat, Shield, etc.; and free access to arcane wands like Blur & Stoneskin (helpful if you don't have UMD or a friendly arcane caster handy). The first two are enough to justify the splash, IMHO; the other two are pure gravy.
Either way I still think the WIZ level is a waste, you get access to wands that you can buy pots of - so what. When you try to wrap too many functions into a build you end up with inefficiencies, all a tank cleric needs is bursty/aura healing and the intimidate to keep attention on them, quicken for mass spells and to bypass having jack squat for concentration. ****ering around with 1 level of wizard just to cast level 1 spells that you don't need (or really even benefit from) or throwing 2 paladin levels instead of fighter (robbing yourself of feats) just doesn't make for a solid framework in my experience and opinion.