I have a feeling by the time this gets posted everything I say will have been redundant, but alas such is how things work.
Farming has made everything cheaper. I don't know if you have been around long enough but you may have remembered a time when superior runes and celestial sigils were worth 200 ~ 300k a piece, and when gold items could easily sell for 100k+. These drops would have happened anyway, it just would have taken a much longer time to happen. The price drop has made things more affordable for a lot of players, it is just a matter of having enough time / patience to earn the money. But still, that is only if you wanted aesthetic type equipment or gear, as the game can completely be beaten without the requirement of runes, or golden shiny weapons, or super ultimate armour.
The only skill to my knowledge that has been changed that farmers use was Protective Bond, and it didn't hinder farming a bit. All of the other skill changes have been due to abuse in PvP/GvG for a slipup on ANet's part.
All of the anti-farming and changes from ANet has been due to bots farming and mucking up things. YES there are bots on Guild Wars, do not even try to claim there aren't. ANet (or rather the representatives of ANet) has made it clear that they do not mind farming or running. They designed the game with these things in mind because they realize that not everyone will want to do the same things as everyone else.
One thing that has boggled my mind though, was ANet's random resets of the prices for traders. The only thing I've heard about it was that it was their way of controlling the economy at random times.