Fishing poles. I had one awesome run, then nothing afterwards the few times i tried to farm runes.
Digging up a map - exactly that. dig every square. plop down a 3x in the middle to sleep after traveling to/fro to drop off the crystal you make and collect runes while you do it.
Shovels, Fishing poles, pick-axes etc, will be in your /recipes, and if they aren't of the right material for you, then craft what you can to level them up. And if there's ever a recipe you don't know, then you need to find it by chance.. or obtain it with the help of staff from settlement buildings.
I understood what you said about the elementals. I'd just never cast one. But I like your new explanation of they work from the caster's perspective so much .. i just stuck it into the notes for the rune.
Again, aside from being able to help carry things, only ranged Mercs staying out of melee have been any help at all. I've gotten a lot more out of Moose and Grizzly since it takes just getting stuck in a font once or twice before you wind up with them nakedly running into melee.. i've had big equipment losses misjudging their staying power and only the beasts have anything close to the Gatekeeper's resilience. As one, it took just a few refined bits of iron before i could farm ruins without having to pay much attention , never loosing anyone.. until my young grizzly died while helping me conquer the first den.
Its not that i don't like them at all, I've hired every last one i've found and have them hanging out, parked at the tavern. My extra pets and domestic animals at the stables :)
Completing a Den gave me a title - which the next level merc wanted to see before joining up. At that time you're not worried about finding enough loot to hire or equip them with and might be a bit more conscious about how you spend your shards.
There's no 'where exactly' in the land. Things spawn, you find them, beat them and fewer things of that type spawn where that was. I can't explain it, but the map contents is always a surprise while you will also always find some landmark, like a castle or fortress just by wandering around. Some things are very rare, but not castles. They seem to start maybe 15..20km from settlements, e.g. 1.5 maps 'over' in any direction you'll run into one eventually. Sometimes even 2 or three no closer than perhaps 8 squares from another.
A good exploration strategy might be to set your compass to the nearest settlement you know about and then to walk to there and back, this way you'll see the map as it really is. say you want to go NW to another settlement. "X" relica and start NW right away. the next time, walk W 3 steps, then go NW.. it never winds up working perfectly, because you'll get distracted by things you find, but you can cover/check the entire space for landmarks that way.