As for astrogha, there is several problems with it, as you mentioned deathgaze kills totems, heals it, and if you stick to iceburst, that one doesn't proc wolf companion curse (because iceburst converts 100% damage to cold, and to proc curse you need to deal some physical damage), and that hurts our damage output.
Astrogha has no timer so in that snese it is just matter of time, hit & run, it will die eventually, I'd just prefere to figure out a way that wont take 30min.
I'm also considering using those 2 pieces:

Question is: it is "solo self found" enough? These pieces aren't rare bases, pretty common set and they are quite nice dps upgrade vs certain harder bosses. You gain crapload of strength, some flat damage, ewd, and not counting 2x 5% procs.
Sheer amount of runs of duncraig you need to hit 125, if you play solo and withour exp gear, you are very likely to find those items.