I hope i can reference other games, because i'm going to.
Eve-
MARKET
Eve has the best game economy i've ever seen. EVERYTHING is player driven, there is virtually no npc "vendors", everything sold in game is sold by players, this is done by "scavenging" aka in eve "saluaging" or looting ships, mining rocks, moons, manufacturing from raw materials, etc.
The major bonus to this should be obvious, and ACTUAL MARKET, not some silly auction house system where buying and sell are completely meaningless because people are buying from a merchant and selling as a middleman. This system really allows dynamic economy and despite some peoples fear of "spreadsheets" it is really quite managable for the average player.
in other words, no NPC merchants. Everything should be player made, player sold, and player controlled as far as the economy goes. This can translate into awesome gameplay as well, because if a clan finds a resource to control, and it remains profitable to do so, there will always be competition for it, as long as the devs don't nerf the area and sell the rare item on a vendor, due to carebears crying.
another thing that i've seen requested in fallen earth, is clan vendor that public can access and buy from, clan crafters can post items for sale, and regular members can post loot and stuff to sell. the clan can adjust the tax on the store. This imo, is the way it should be, lots of stores, with clans/tribes, whatever selling and driving the economy. Clans could be established in areas that have specific mobs that drop X loot, and actual be known in game to have the best supply of X, while the same applies to other clans.
if any game needs to do away with npc merchants it's fallout, make a prospector skill to allow more sell orders, etc.
CRAFTING-
This is being discussed in another forum, so by all means, discuss it there. but i wanted to touch on things from other games that could help.
Specialization is key, you can't have every cotton-pickin crafter making every cotton-pickin item in game now can you? well you could, but then you'd have fallen earth style crafting where nothing is worth anything to anyone because everyone can make everything.
and SWG style specialization would be good, at a certain level, mid-point to cap i suppose, a choice to specialize should be made, i'd say 1-2 specializations, 1 major and 1 minor, or just 1 major. This limits the availability of high grade items, and makes crafting a viable playable class in game.
I don't have a lot to add on the actual mechanics of crafting, i didn't mind grinding mats on fallen earth, or the fact that you just fill up the que and it ticks offline, that's fine with me, plz don't make a mini-game. that would just piss everyone off, that's fine for a console, but we are going to be making literally thousands if not tens of thousands of items in this game. a mini-game will drive us nuts.
CONTRACTS-
another eve feature that would be absolutely fantastic, player creates a contract for X item, player accepts contract, gets the items, completes contract, or fails it and pays the collateral.
you can use this for anything. i like the idea of courier contracts a la the mojave express crimson caravan, players could have high cargo limit vehicles, or skills that allow them to carry more on thier vehicles, so moving stuff could always be an option. This would be a crafter type skill. Again, you set the collateral to the cost of the items, and if contractor fails, he pays the collateral. With a little bit of thought, players will start creating fake contracts and try to gank ppl in the middle of the courier contrac to get the collateral and the items back, but imo, this only makes the system more apocalyptic and interesting. perhaps some way to warn the courier if this has happened before, so that possibly they could set up a counter ambush.
LEVELING and SKILLS-
some differentiation would be nice, example: your combat/missioning or ACTIVE skills use experience from missions and killing things to level
and