How many of you have played the game without even remotely starting the MQ or the Expansions?

I'm just curious on how it affects gameplay if I don't pay my initial visit to Caius Cosades.

My very first playthrough was done entirely that way, and I never had any problems with it. At a certain point I did find Sunder, Keening and was perplexed that I died whenever I equipped them.

I just wandered for in game months...until my fame got high enough for every important npc to begin bugging me about the main quest.

I have never done the MQ and my game is perfectly fine. Btw you should have added a poll here

It's very rare that I ever play the MQ.
I usually just join a Guild or two and just wander around. (or busy playing quests from mods)

Ignoring the MQ doesn't affect gameplay at all, except for some interactions/dialog with certain NPCs.