I know, its not all that big a deal to go back to your house. If you don't want to go back to your house take everything you need with you before you leave.

Although it's not really that difficult to go to your house, it's not like it would be "bad" or even necessarily time consuming for the staff to make a bank where you can stash your plat or something.

A bank is a great idea, and wouldn't make houses useless. The bank would, after all, only store plat... not diamonds, wooden boards, cannonballs, furniture, weapons, armor, etc.

And if it so pleases you...perhaps an interest rate? I don't fully agree with my own suggestion, but let's just debate it.

No. Interest rates in modern economies serve an inflation-controlling purpose that they wouldn't serve in the Graal economy.

Good point. Perhaps, rather, a weekly fee for keeping your money in the bank?

Good idea that way the bank will not get over used and people won't have a bank account when they gold runs or leave for some time.