I want to come back to the game after journeying all these years between morrowidn oblivion skyrim mount and blade zelda and various FPS

However, I want to do this with the absolute most epic modded adventure for a thief to find ADDITIONAL game play / immersion.....

Practical guilds , quests , buildings , merchants , environments....

I want to just essentially RPG my way into King pin of the world... but I want to do so through a very meticulous very thorough Progression starting from zilch... entering into EPIC...

lol to be honest all I can think of is..

Balmora expanded, thieves guild expanded and some various merchants / bank mod.

Could anyone help me get a thorough investment mod install going for me?

the uber thief.

Some old mod lists could be worth a look:
http://www.mwmythicmods.com/mercantile.htm
http://www.mwmythicmods.com/thiefassassin.htm

You may need http://www.tessearch.com/ to find some of the mods though.

Haldenshore & Havish

Depends on what you want to do. I organized some mods that I've tried before, can't say their all lore-friendly, but that's for you to decide.

New Gear:

Antares' Little Mods (Arcimaestro Antares) - especially traps that you can buy, set, and reuse.

Dave's Furniture Store (Dave Humphrey) - Thrift shop has some new thief-relevant gear.

Immersion:

Camonna Tong's Violence (Arcimaestro Antares) - Makes the Balmora Council Club a lot more hostile.

Beware of Pickpockets (Arcimaestro Antares) - They can steal stuff from you, need a high sneak skill to defend.

Give Your Orders (TheLys) - Let's you give orders to people of lower rank, like other thieves.

Rectified Fines (RPGingmaster) - if you don't like the guards taking everything you've ever stolen when you get caught.

Abandoned Flat (GhostWhoWalks) - Adds an interesting home with a serious lock. Lots of interesting training options for a thief.

South Wall Den of Iniquity (Balathustrius) - Better thieves guild in Balmora.

Guildmaster Bonus (Moobler) - some benefits for being in charge of your guild.

Difficulty:

Bounty Hunters (Arcimaestro Antares) - baddies will start tracking you down if you have a bounty of 500 gp or more.

Guard Expander (Caine) - more guards around.

Disarming Traps (samurai?) - makes probes have variable difficulty, usually in line with the lock difficulty.

Gravedigger Bob (????) - Lots of interesting stuff laying about for the taking, until you try to take it from Bob.

*Children of Morrowind (Emma) - weird choice, I know, but those little buggers show up in some really inconvenient places, making thievery more difficult.

Quests/Missions/People:

The Sable Dragon (Pluto) - Adds an inn with a lot of interesting characters, quests that are thief related.

Vvardenfell Druglord (Fliggerty) - Maybe not straight thievery, but contributes to the smuggling/skooma side of things.

Hlaalu Vault Extended (Serenia) and Redoran Vault Extended - More satisfying.

Dungeon & Diamond (Arcimaestro Antares) - Adds a small crypt/dungeon that's best for thieves.

Annastia (patrograd) - Adds a city of thieves, and much more.

Well my friend you certainly have all beefed up my mod implementation desirE!!!

I am going to hopefully have a successfull clean install on these and run the game like never before... much appreciation!

if only my nexus manager would work for morrowind right now.

Extra faction quests:

Hlaalu Business (4LOM)