So the first thing people theorycrafted Primal Dungeoneer on was the Doomhammer list. It's obviously a good tool for tutoring Cagematch Cust. + Atk boosting spells, but I'm sure there's plenty other ways to utilize it.
For example, Lightning Bloom + Marshspawn seems like another good package to tutor from your deck. Both cards are reasonably easy to fit in most shaman decks (let's face it, that Poisonous 3 mana 1/3 is nice value card but it's too slow for Thrall).
Midrange Elemental deck could benefit from Vivid Spores + Menacing Nimbus. Seems sticky enough to get you through board wipe or two.
What other uses have you guys thought for Dungeoneers?
I've been experimenting with this Burn Shaman. It has potential for more, but i'm looking to see what really works well, and what could be cut. Somewhat in agreeance about Venomous Scorpid. May drop Rune Dagger as well. Mankrik and Lady Vashj might be some good additions.
Mankrik has some anti-synergy with Dungeoneer, but at least it cycles itself after summoning the 3/7 token... which might not be a bad thing either. Interesting idea!
I don't think Vashj is good in this type of list. You've got several high-cost minions in your list and no reliable way to fish the Prime, and on top of that your spells aren't that expensive to begin with. If you want more spell tutoring in your deck (which might not be necessary), try Malygos. Or just a Cagematch for tutoring out the Dagger.
Personally I'm not a fan of Dunk Tank. In burn shaman list it's usually 4 damage "Deal 4 to face", which just feels way worse than Fireball. I'd rather go for pair of Wandmakers because most of the 1-mana spells are above average for burn shammy (Lightning Bolt, Devolving Missiles, Primal Studies and Guidance). That gives you a chance to get dual-class spells without flunking your Dungeoneer's draws.
These are just some random pieces of theorycrafting w/o actually playing your list, so take my post with a grain of salt.