First, I'll explain how I play, to give a perspective from my character, that will be different from that of a leveler for example: I try to find a place in Yliakum's society (basically, a trade). I quest a lot, for the fun of it (the quests are far from crap; I can see how they are evolving, and it's going to be great). And I RP constantly (meet people as you meet your townsfolk in RL, and see where it leads).
I do need to train skills to achieve that. Since my character creation main skill is not implemented, I have chosen to repair weapons, because I found that not many people do so. And I also keep practicing mining. I therefore grind rather slowly, not focusing on it for too long at a time. For example, I stop by a gold mine each time I travel near one and to a town; for the sake of grinding, I could just dig iron, as it is much faster for some reason. I did it once, as an OOC testing session.
By training slowly and intermittently, I don't find grinding boring and I think that the progress pace is rather good. Except for combat: I once gave an alto 30 levels of both sword and armor in 1 game session. But for other skills, I find it ok.That is because I don't spend my time only on training. Roughly, I alternate chatting, questing, mining and repairing (although the latter is 99% fighting to damage weapons). I find the training extremely unbalanced, but that's another story, that doesn't affect the answer to the original question. Limit yourself, and not only does the pace feel right, but also things are not so mindless and repetitive. For example, I try to always have a magical armor when I travel in the wild, but I don't cumulate the spellcasting (unlike I did for my first levels). I stopped metallurgy at steel stock level, so I do need to meet people to deal with my gold; and yes, considering my time zone, that means that I do sell it to Trasok or Harnquist sometimes, since their places can be very empty.
As I ran out of quests, my routine has been more centered on training lately; but I won't spend hours doing the same thing, so the only result is that I play less, give myself excuses to change town, and revisit all the NPCs one by one. I don't think a MMORPG is the kind of game designed to be played 12 hours a day for 2 weeks anyway; more like once in a while over a long period, and even with breaks.
So, no, I don't interact less while grinding. On the contrary. When I interact less is when I'm running between places and when I'm focused on the NPC chat tab. I chat the most at mines and smiths, and sometimes when meeting a resting traveler.
Now, when I'm at a mine (mostly Oja gold), or at a smith, it's often all silent, even when it's crowded. I always make some noise, but rarely get an answer. People always answer a call for help on the other hand, proving that they are not deaf. Well, if it is that boring, and if one can watch a movie at the same time, I'm starting to understand. Indeed, the issue is fun, and that's not an easy one to solve. I've also heard, and experienced to a degree, that a lot of windows need to be open, which keep crafters isolated in their bubble. Maybe working on that aspect would help some of them, give them more PlaneShift immersion than GUI immersion?
My point of view will never match that of a pure leveler. There's no way a system can provide the same pace for a mechanics-bound RPer like me, and for a duelist (RPer or not) who wants to quickly boost his skills to have fun with PvPs. This doesn't affect the old characters interaction issue anyway. Grinders can chat as much as anyone else, if they want to. And for the one who doesn't want to, it doesn't matter if he is digging plat or cooking apples; leave him be.