I want my next character to do all the questlines. I have him in my mind, his personality, who he is going to marry, and all that stuff. But, I have no idea what kind of build to do.

What kind of build can fit in all the questlines?

Any build can fit into any quest line. There are no skill requirements for factions.

Heavy armor in the thieves guild seems wrong though.

Im talking about like, what make sense.

Mostly I dont know what kind of build I want, so I was wondering what a jack of all trades build would be like. Workable, not underpowered.

There is at least one TG member who sports Heavy Armor in the game.

You don't need an uber character in any skill to be successful at this game. My first character was a Jack of Trades, however each character after that was more focused and only did factions/quest lines that fit their Roles. I had a lot more fun with the second group. I have rolled a character for the Thieves, one for the Assasins, one for both of those, one for the Civil War/MQ, one for just exploring (although my first character tends gets pulled out of retirement for that), one for the Companions, one for Dawngaurd, I reused a character for Dragonborn.

Most of my characters are done with what they need to do by level 30 or less, and I don't really pay attention to the character level, just my skills.

In other words, you can pick the skills you want to play with, and you can do the quests you want to do and the game will not limit you in any way. However, any self imposed limitations, well, you have to make those up on your own.

I had a character like that, he was a completionist and also my first character.

He didn't really fit in with either the TG or the Dark Brotherhood. He would just do those quests in Heavy Armor.

DB doesnt matter your skills, you're an assassin baby!

It's fine. Most of mine are like this and it always works out. Besides i find the game more enjoyable when you have access to everything.

Power hungry Dragonborn who mixes up using one handed weapons and shield in melee, daggers for sneakiness, bows for range, magic of choice for flavouring and healing and who wears a mix of heavy and light armour to get the best look! Or alternatively who wears light armour or cloth when doing less melee intensive things, and heavy for when wading into battle with a weapon and shield.

With the armor cap you can get your smithing high enough to wear whatever you want and still absorb the maximum amount of damage. It's kinda lame because your 3k armor Dragonbone protects as well as your suped up leather armor, but that's how the game is programmed.

On the plus side, you can wear standard duds from any faction and fit in anywhere. This way you don't have to sacrifice functionality for aesthetics.

I always do all the quest lines. Somehow always manage to write in a rp idea that makes sense as to why I do the quests.

Ha, ha, I did the exact same thing. Then I decided to quit those two questlines because it wasn't making any sense.

I have a JoAT and nope the game doesn't try to prevent you from being one or blocking you from quests.

Just focus on being sneaky with magic for backup and rely on melee alot for the tougher fights. That's how I do it.