Cross realm zones bring the number of players per zone up to the intended number, the number we had in mind when designing the zone. The competition over mining nodes you're experiencing now should be on a par with those who are on realms with a high population. Your profession levelling speed should be roughly the same speed as everyone else.
While I can understand that you enjoyed being able to level up gathering professions quickly before, it wasn't ever meant to be that easy.
Thats nice and all, but if the amount of competition over nodes and mobs should be at this level, I seriously wonder if the devs realised that the amount of mats needed to level professions is very much off the scale. You will level multiple times from just gathering proffessions. And the time to do that now takes way longer then it used to be, and it already used to be bad, especially during the 1-425 skill levels.
Certain ore is already hard to get without competiiton, especially Cobalt and Fel Iron are very hard to get enough of to level crafting proffessions.
They are spread thin and with more people farming the nodes, there are even less nodes. And this has a BIG impact on server economies. It used to be, that when 5 people over 5 realms farmed 1 type of ore, the amount of veins would be 5 times as high, since there were 5 times as many servers.
Because of that alone prices for low level herbs and ore are going up. Wich is anything but a good a thing, because prices for low level mats are already idiotic; 20g for a stack of copper, or 20g for a stack of peacebloom are quite comon. And so not only gathering the mats is harder, buying them on the AH is also much harder since there is fewer on the AH or they are more expensive. And there is no way anyone will buy a low level uncomon item for twice the price it was before MoP...
So to sum it up:
Mats are being spread out over multiple servers instead of 1, wich causes them to become rarer and with it economies get issues with demand vs supply. And thats caused by the amount of players per zones due to CRZ.
CRZ therefore causes issues where there was none, and does not improve anything. Anyone had a CRZ group for a quest lately? Ehm? no? or hardly any. This simply because there are only a handfull of group quests wich are mostly skipped due to sucky rewards and people outleveling zones so quickly they don't really need those quests anyway.