The water problems on the back of the house were major, but those on the front were fortunately pretty minor. Regrettably, they existed nonetheless. When the stone siding was installed, the bottom wasn't flashed, so water was able to get in underneath the stone and caused some damage to the sill plate. Fortunately, the sill plate had not yet rotted, so it didn't need to be replaced.
Flashing needs to be installed where the wall intersects the deck, and two options existed: 1) remove the lower stone on the wall, install flashing, and re-install the stone -or- 2) remove all of the stone, flash the bottom of the wall, and install hardiboard siding. I chose option #2 because it was cheaper, hardiboard is more water resistant than stone and mortar, removing the stone gives me an opportunity to better insulate this exterior wall, and the stone gave the house a dated look.
Yesterday was spent taking down much of the stone siding.