Additionally, crafting XP could be scaled up accordingly for certain items as it wouldn't be one person buying a lot of wood and grinding out fence posts, but a single class making money and getting XP while doing it. As Wolf said, we are playing a multiplayer server, thus while you it possible to play as a lone wolf, the lone wolf style of gameplay should not be defended in order to limit the amount of interactions a community has simply because people don't want to interact. A community is social and fluid, the more barriers that are erected between classes, the more interaction and socialization that will happen among the MAJORITY of the community.
Also, this is not some hypothetical idea. On the first server I played, things such as gates, doors, and lifts were all free of charge due to a wide array of donors being able to use them. However, for a bit of wiring and a few gate signs I have been paid in excess of 100 C on this server. Limiting the things a player can do INCREASES [Usually from 0 or near 0] prices and CREATES new markets, which is good. I expect the same thing to happen on this server if things such as fences are limited. If you want a fence, why not buy it from someone who's profession it is to make fences, thus generating both a player interaction AND a new market for fences that previously did not exist due to it being widely available. It is a basic part of economics, markets must not include everyone in them in order to be largely successful.
While I love the idea of iron doors being Mason only, neather fences seem like a cheap way of saying fences are Mason only, but in actuality netherrack has very limited uses outside of making fences. Thus, a market for the raw good was never there in the first place [To much degree, at least] and therefore the fences would somewhat create a market, but have a much lessened effect on the massive transfer of raw goods around the server. Basic, decorative items are what need to be limited. I can build a house out of plywood, but building furniture, fencework, a stove, putting in power, all that decorative and useful jazz I would usually need to part out to someone else in order to get done. The same logic applies here, allow people to build their houses, but any finer details will need to be purchased from people around the server. I would also advocate the elimination of Chest shops in this context, but due to the merchant class much of that is already being done. I personally HATE chest shops because of the inherent laziness that they embody in the community and the lack of any true market aside from sign clicking. If I want to buy 50 gold, do I feel like I am part of a larger community when I buy it from a chest shop in a random town, or if I buy it directly from a miner who just worked for 2 hours, had a short story to share with me, and not has been rewarded for his work by me, personally.
I feel like this issue really hits an important note on my outlook for the server. If everyone is going to be crafter now, items need to be exclusionary in order for any market to function to the current degree even. Instead of buying service industry items that are currently the only non-resource functions that are traded, such as architecture, redstone work, and of course masonry sign abilities, resources should be funneled down so that they are exclusionary and thus force people to interact in order to make the best of their server experience. I advocate people working together, I advocate people who want to be lone wolves, but I also see that there should be inherent disadvantage and advantage to each playstyle. If a person plays a community style game, then he should have access to resources easier and also be limited by the thought of the other players, but the opposite should also be true for anyone who wants to play a lone wolf style. Not everything should be self-obtainable, that increases hoarding and stagnates the server economy as large quantities of raw goods that could be turned into anything are sold instead of finished products that should have a higher value due to more work being done, but actually do not because of the disadvantages of not having a good that can be freely transmuted from a raw form to any item that the person wishes.
Tl;dr, I do not believe in TL;DR statements.