First, I'm RP'ing so I want the decisions to be logical for the type of character I'm playing. My character is a Dunmer from the former House Hlaalu (I assume the House system was destroyed after Red Mountain exploded) and I tried to shape/play him based on the lore. Having said that the essentials are:

-I don't use magic except for the default Heal spell - persoanlity quirk
-I wasn't going to join ANY factions except the legion
-I'm a minimalist and any extra/unnecessary weight irks my core - so "quest items" that can't be dropped are...bothersome

It seems despite all my efforts I'm not going to be able to be this character. It seems at every turn I'm picking up some quest item or coming to the realization that the trainer I want is in a guild and only trains guild members.

IIRC, you have to join the Thieve's Guild during the MQ so I reserved myself to that but I was trying to avoid joining any other guilds.

This brings me to my current problem: what started as a simple trip to get a shout has turned into a multi-dungeon quest that ended in a locked door only accessible by members of the Mage's Guild.

This isn't the first time this has happened and I'm tired from the mental energy I've exhausted trying to navigate the numerous guild-traps in Skyrim.

No mas.

My dilema now is trying to figure out how to transform the type of character I wanted to be (a non magic using somewhat honorable Dunmer loner) into one that would join guilds.

I feel I have to do it otherwise the game might become unplayable. I'll join the guilds if it means I can play freely and regularly get rid of "quest items" without using console commands.

In my mind, there's simply no person in all of Tamriel who would ever be a member of multiple guilds. It just doesn't seem like the norm for the world.

I could be persuaded to think otherwise.

So, the question is: why does a Dunmer descendant of House Hlaalu come to Skyrim and end up a member of multiple guilds?

First off... quest items really don't have weight despite what the description says. As for the rest, I haven't run into a situation where you were forced to join a guild. All of my characters so far have only ever affiliated themselves with one organization...... Still a lot for me to play though, so maybe I will run into your problem eventually.

However, don't fret the quest items, they don't weigh anything.

You could roleplay he has no interest in the guilds themselves, but sees them as a means to an end.

He is an imperial that fights the dragons to keep Skyrim safe and a part of the Empire, right?
Maybe he learned through his studies that a powerful weapon to fight dragons (a shout) is locked away somewhere and only the mages guild knows how to get it.
That could give him reason to join.

And who knows, maybe during the course of events he will come to care for them.

As far as the mages guild thing in the MQ goes, you do not have to join,

You don't have to join the Thieves' Guild for the MQ either. When you're asked to get information from Brynjolf, just go to the Bee and Barb instead and talk to the innkeeper.

Thanks for the replies!

I didn't get the "Dragonborn" option in my other playthrough when trying to get into the college...I'll try again. The info on the Thieve's Guild is also helpful.

The problem was not only a weight concern it was the clutter as relating to the quest items. It's good to know they don't really weigh anything but I still want them out of my inventory.

I'm going to follow Merari's suggestion to some extent. I'll just join the legion and RP as an Imperial Special Agent tasked with investigating the Skyrim situation.