[Micah]

Flame storm is F5, any Anointed can cast it with a simple Phoenix Power casting, I don't see all the fuss with communions.

They can also summon Scorpion Men with base paths, contrary to what the OP seems to imply.

The demon lords have all of the paths except water and astral between them, but they're expensive and pretty late game. It is a last-resort option for diversification though. Astral magic is really good also, but the EA Warlocks are fairly weak in both.

Nature is always an option via indies, at worst, and then you can start site searching for enchantresses, which open up much better nature and all the elements and seem to be fairly common.

Playing the mid-era version of Aby in MP I found that establishing a good trade partner early on will greatly aid your attempts at diversifying. Hellbind heart mage-trades are especially good for you if you can get a trade arranged. Negotiating for an air mage is especially fun because you can trade with anyone on the map with cloud trapeze, so you can afford to shop around a bit in a large game. Try some of those ideas, see if it helps.