@jinoue - In this post @franz mentions that he is using garden hoses -> Fricking Flex Love!, so what you want to do is possible. And see this post from @IoTEric on how he did the same thing -> Setting up Rachio to Control Sprinklers W/O an Irrigation System
Regarding drip systems - YES, Rachio is designed to handle them. The referenced spreadsheet is to get the precipitation rate correct.