I love the Helgen idea (always wished we could've gotten involved in rebuilding Kvatch in Oblivion).

Houses (including housecarls) requiring weekly/monthly expenses is good too, and might increase replay value if it made it harder to own numerous houses.

Another wish of mine is that becoming a faction leader required (or at least allowed) one to *spend* money to build/maintain its headquarters and expand its influence, perhaps even acquiring property in cities/holds, recruiting/training new members, etc. This would especially rock if there was a faction reputation system.

I have over 10,000 gold ingots sitting in my safe in the Arch-Mage's Quarters. I've toyed with the idea of throwing them into the Sea of Ghosts, one by one, until they come out of the sea and rise back to the ground level. then we fuse them all together, and boom! Winterhold has more landmass for it to rebuild. A very rich foundation too...

High stakes gambling with reload proof system needed, and lots of stuff to buy ( wigs, dwemer motorcycles, home extensions, guns, items with new animations, Aureal and Mazken slaves ) needed.

in two world 2 there was a village mode where you would own a village, buy buildings and stuff.. this would be good for skyrim. in two worlds it wasn't in the game world itself, if it was in skyrims world it would be awsome, and give a customizable area players could care about, putting money into shops could make people wealthy, and npcs could have parties and have better furniture for the houses you build
you would be able to build things to help defend your village, hire guards tax people, get attacked by bandits and have to defend and a bunch of other things.

True, some exquisite items should be so expensive that you can only afford very late in the game. It gives you motivation to practice professions and loot dungeons.
Besides the already mentioned money sinks (farms, castles, ships, player own faction) I would add donate any amount of money to temple/beggars and see the consequences (the temple buys new statues and decorations, the beggar will rent a room and buy clothes and be grateful, etc); or start a newspaper/ horse courrier business. You shall need couriers, horses, carriages, ink, paper, and everytime you want to release a new paper, it will take the latest events in the main quest / guilds and put it in the form of news. Your people will spread them in real time into the territory and people will start talking about the news (like Oblivion's random conversations).

All great ideas

A resounding yes! I would definitely enjoy more vanity content. (I would LOVE for them to fix the current house decorating bugs that randomly regenerate carefully placed items all over the place, where they were first dropped, etc. I have essentially given up decorating my houses because its a complete waste of time now: if it isn't nailed down, it isn't where you left it!! In Oblivion, it was awesome; very few decorating hitches.)

I also want to craft Circlets. Basically, at some point in the game, you should have the option to acquire the abilities to learn how to make just about everything, if you want to, and sell them. Buy the materials, set-up wholesale accounts with merchants in other cities, import/export...

Buying land, upgrading to estates, towns, cities, kingdoms...I would get started on that in a heartbeat, main quests be damned. I love the above suggestion about Ebony houses & gold diamond statues... hell yeah! Give me something to use all my accumulated materials on.

I hoard shiny things. Ingots, jewels; I will one day have enough to build a 24k castle--and totally would if they let me v.v

I also want the option to make/import silks, velvets, rare furs, and craft clothing. Finer furniture. Whatever. Breed horses, dogs.

Capture, train, outfit, breed dragons. Seriously, there should be a Shout for that: Tame Dragon for 59 minutes. Hop on and fly over Skyrim. Wears off, he tries to eat you...

And of course my Pony Package thing--train (pay) to be able make Horse Armor & improved Horseshoes, different Saddlebags to equip, Veterinarian Alchemy, whatever.

(sigh)

I would kill for the possibility to build a solid gold statue of my character in the middle of Whiterun (or whatever your favorite city might be). ^^

If anyone has played Nehrim, there was a shop in one of the cities where you could buy a large variety of powerful items but the cost being very high.
It acted as an end-game gold sink and it always felt like a big decision when buying something there. Might be good to include something like this in the upcoming DLC.

There is a traditional solution for the over-wealthy... BUY A BOAT.

This is Skyrim, and we're all Vikings (or Nords or whatever), a boat could provide coastal fast-travel, trading and raiding opportunities, and of course endless expense.