Ok so here is a list of some things I would do.
Guild TPs
Special rune-stones can be bought or found (ultra-rare) in the grass and bushes. What they allow you to do is teleport to a guildmate by going on their profile and pressing teleport under more actions. Every teleport uses one rune and takes a few seconds for them to vanish and reappear in certain locations.
Banks and Donations
For the bank you should make it so you lose 2.5% of your gralats when you did (for instance you would lose 25 gralats if you had 1000 and died). Then make it cost money to start a bank account and extra for more storage and a bank card. There could also been a 5 gralat fee for depositing and withdrawing and donating. You could donate to your friends if you had a bank card by finding them in your friends list and pressing the more actions button and then tapping on donate which lets you set a certain amount to donate. For all transaction you need to be depositing a least 25g or withdrawing at least 25g (same with donations). For a bank account a starter should be 1000g and hold 25,000g, a premium bank account should cost 2500g and hold 500,000g and an elite account should cost 1000g and hold unlimited gralats. A bank card will be 5000g and let you donate, gain interest (interest is 0.5% per day on a starter acc, 2.5% on a premium and 10% on an elite), deposit gralats at any bank branch and take out loans (5% interest per day on loans and it automatically pays back the bank when you gain money, also you get your bank account removed and your furniture taken of you don't pay back for six months). The amount you could take out on loans would depend on your account, starter would be 1000g, premium would be 5000g and elite would be 25,000g.
Wallets
Basically all this does is limit the amount of money you can carry. The default wallet would hold 10,000g. A large wallet that would cost 1,000g would hold 50,000g and a Mega Wallet for 5,000g could hold an infinite amount. Of course the bank would be safer because you wouldn't lose gralats when you die. If your wallet is maxed out you simply can't pick up rupees so other players can take them instead. If you find a chest with rupees it will say "Your Wallet is full!" and the chest will close back up allowing you to go to it later.
Dropping Money on Death
As I stated in the info for the bank I think players using carrying gralats in there wallets instead of the bank should lose 2.5% of their money when they die. Since its a percentage the more you have the more you lose. Say you have 1,000 gralats, then you will lose 25 gralats if you die. This is an amazing thing for PKers and of course you wouldn't lose gralats when you die in a spar and maybe it could also be disabled for towers and quests.
Marketplace
Markets would be amazing for people to sell their items. Twice a day the market will open for an hour (once at 7am and once at 7pm or something like that). A player can rent a market stand for 500g and sell as much as they would like for 15 minutes. Once they rent a stall they are stuck there until the time is up and special GUI appears. It has two buttons "Sell" and "Quit". If they want to stop selling in that 15 minute period they press "Quit" and will not get the money they paid to rent the stand back, however of course they keep their profit just like if they stayed there the entire time. The "Sell" button opens up their inventory where they can choose items such as customs, hats and morphs to sell. Once they have chose what item to sell they can pick the bidding price. When a shopper goes up to the stand and touches it a GUI will appear saying "Buy". When pressed it shows items they can buy in GUI inventory styled screen and the prices for each one. If they want to buy it they need to bid an amount of rupees for it. It will be like a massive chat screen and show each players bid, your current bid and how many gralats you have currently. The highest bidder will get the items. Also on weekends the market is open all day long! There will be about 25 market stands.