Any ideas on a good leveling spec, mostly solo, but some duo with a zerker

For a final spec 8 / 46 / 27 (heal/buff/cave), i would do that :

level 10 : 5/4/7
Then up buff to 12 (level 15)
Up cave to 20
Up heal to 8
Up buff to 22 (if u still have often a zerk with you, otherwise, let buff at 12)
Up cave only until lvl 40
Respec cave if needed at level 40 with free respec to reduce it to your final specs, and up buff.

My sham is lvl 44, i put more points in buff before lvl 40, and solo was possible, easy and safe. No downtime to kill yellows, but it's not fast.

Thank you, I am 0/6/9 now I think, or something close to that at level 11 and I can take out several yellows before needing to rest, prolly about 5-8 and my power comes back real fast, I can act as a heal/buff bot if im duoing.

Taking out Oj's is pretty easy too, reds are also doable but not mana/time efficient