I sometimes have an urge to replay specific quest lines but not enough to make a new character, I would prefer an option to replay quests

I do all content on my main because I want as many achievements on her that I can get. After she does the content, I will run a couple of alts through it but don't worry about doing everything with them.

The main reason is that my main character isn't a lying, pilfering, murdering git.

... now, my second character (an older gentleman, and born survivor) has a moral code that is a little more flexible.

I tried to just do all the quests and stuff w one character, but got bored and decided to make an alt. No way Im running all the same quests I just did.

My main does everything. Only thing she hasn't done that another char did was the random trial my DK ran.

I have one main doing everything in each zone and alliance questlines / main quest line etc

I have a theif for TG & DB. Getting into thieving and excelling at it was a job in itself. Was cool.

Otherwise yeah i do the lot on my main toon. Crafting ,PvP the lot.

My templar's morality will not allow her to do the Dark Brotherhood storyline, but my Dunmer mage just smiles and does what needs to be done.

I'm not sure how to answer.

I have 1 character who is going to eventually do everything except probably the Dark Brotherhood quests, literally everything - every quest in every map, every dungeon, all the skyshards etc.

But I also have another 5 characters (not counting my mule and crafter) who I'm going to do the main storylines on and a lot of other content. Each one does things in different orders, or in different ways, but I'm planning to play through most of the game on all of them.

My main character is the one who quests through all of the content. I have a bit of a headcanon throughline to her story as I go along (as recorded in a thread in the fanfic section) that thankfully has progressed quite steadily as I've gone through the various zones. I wasn't sure if she'd be into the murdering thing, but fortunately Orsinium put her in a good (well, maybe I should say apropos) headspace to venture into Dark Brotherhood territory.

Beyond that I've done small bits of questing with other characters, and theoretically intend to play through full questlines with some of them, but that probably won't happen until I'm done with everything on my main.

This is the best fit answer for me, but my main character is likely to do most (not necessarily all) of the DLCs. No matter how much I think about how to make it work, I can't see her doing the Dark Brotherhood content.

A "Main" per Alliance & a new 4th character for Vvardenfell

I have my main, the character I first created do all the quest related content. Main, DLC, Dungeons, etc. but its not really suited for anything else but normal difficulty and fun. At least, I'm not learned in its style as a magblade on how to use it for trials and such. I use my 13 alts each for specific content.

My Main, a Dunmer MagDK, is my Ebonheart Pact Vestige who defeated Molag Bal, saved all three alliances, cleaned up various messes in Wrothgar, and grudgingly solved Vivec's problems after he ignored her advice that maybe, just maybe, hanging a gigantic rock over his shiny new city is a recipe for disaster.

My second major character, my Breton Stam Sorc, is a minor noble in House Montclair with a huge grudge against vampires in general and one Verandis Ravenwatch in particular. She ran away to the Godl Coast and rose to become the Silencer of the Dark Brotherhood and has been serving as a murderous troubleshooter for various entities like the Thieves Guild, Queen Maraya, and Divayth Fyr ever since. She's currently working with Divayth Fur because when he said he wanted some capable muscle for his trip to the Clockwork City, who's more capable at murderous mayhem than a Dark Brotherhood Silencer?

I've got others who all have their own story and content, like my Nord Stam DK who's working her way through saving Skyrim in Eastmarch and the Rift, but those are my most developed characters.

On my main I do everything when it isn't new. Having said that, I do level up my Alts with content more suited to their "story" (dark brotherhood on my assassin nightblade), Wrothgar and Orc quests on my Orc warrior, etc.