A Player picks about 4 different trade routes, spread out wide enough to cover
most of the population centers. On each run you have several skill-less
runners (possibly with some stealth, and possibly with horses and arms) simply
doing the run. If necessary, station a trader at one or both ends to do
the purchases/sales. You now have a way to generate profit on cash. You can
minimize risk by having several runners, with the money scattered among them,
and have the runners WAIT SYNC several times during the run so that if one
courier is killed, the rest will not run into the same trap.
The first bank function to perform is deposits/withdrawls/interest. To
deposit money, a player must arrainge a specific place and day, and the bank
doesn't take responsiblity for the money until the day after the deposit. The
money is given to a specific representative of the bank. This unit quickly
hands the money off to a runner unit (whose identity is kept secret by selectingthe unit from the pool of runners) who leaves to rejoin the trade run. So,
fairly secure deposits. Interest is simply generated by the money-making scheme
given above, with some percentage kept by the bank. For withdrawls, a random
runner unit gives the money to the player on a date and place.
To get fancier: Wire transfers (transfers between banks) can be handled
for a fee. The player deposits the money at one branch as above, and at the
beginning of the next month the money can be withdrawn at another location.
An established bank can absorb the flux simply out of the pool of money in
the given locations, though a runner unit can balance the pools of money
every once in a while.
Loans can be handled like withdrawls. The player acts as a loan shark,
charging large interest and killing faction members when the owner doesn't
pay. BTW, monthly payback would be too hard, and loans should be based on
repayment in full at some future date.
So, under the current rules, banks are very do-able. An older player could set
one up on his own, as could a coaltion of newer players. It requires no
special features from the game system.