I find this to be vastly overstated. I navigate both areas and never have issues. In fact, except when I'm in Meridia, I habitually return to the marketplace prior to logging off any character or quitting the game. And I never have navigation issues.
Changing PvP to private instances won't eliminate the chatter on the general chat channel. All of the public channels are so full of pointless and meaningless chatter now that I have them all turned off for most of my characters. I leave them on only on my haggle bard because he does all my shopping and selling -- which makes using Trade and General chat a sometimes useful tool.
If you don't like the chatter then disable the channel. What do you use it for anyway? To find groups? That's why there's a grouping tool. To talk with friends? That's why there are private channels.
No, instead of eliminating PvP how about eliminating general chat? It makes just about as much sense. I can cry about how annoying general chat is -- or I can turn it off.
Same with PvP. I can whine about how bad it is, or I can not participate.
Neither affects my ability to play the game. If it affects my enjoyment I simply turn it off -- problem solved.