Also gone through 2 games already without finding iron resources. Plenty of horses and refugee camps though.. Edit: correction, I found iron, just too far away (and ran out of essence) to use. Also naturalist doesn't appear to be working on custom characters

Same.  Seeing many maps with no iron and at best maps only have 1 iron.  Would like to see at least 1 iron type resource per player.

Naturalist is definitely not working at present.

I'm beginning to wonder if there should be some kind of building that could be built sans an ore mine just to give a small amount of ore.  A caveat would be that it could only be built on certain terrains in their city's territory, kind of like how the Miner's Guild could be built in MoM only if your city had a hill or mountain in it's territory.  Leaving an actual ore mine as a rare resource indicating a huge ore deposit which not only give you a lot more ore, but maybe some kind of other bonus too (better quality iron or some such)

This way it wouldn't cripple a player/AI that wasn't lucky enough to have a large ore deposit.  Magical ores are different of course, but plain ol' iron ore should either be really plentiful or not be so crucial to developing anything but the most basic of units. 

A good real example of common iron ore is bog iron.

Just my two cents.

You just research traing type techs then when recruiting change the training level.  Think Elite is the one with 15 hp.

Some sort of black market type system like in Sins of a Solar Empire, but I would go a step farther to keep it from over-balancing the mechanic of limited resources - rather than the exchange rate go through the roof, make it so there's 17 metal for 5 turns, and it doesn't replenish if someone buys it all.  Next 5 turn 'period' 49 metal is available, and so on.