Yes, I monitor contact open/close conditions with a temp limit module, washer monitor, dryer monitor, house power monitor (use a relay plugged into an outlet and monitor those contacts), garage door "wide gap" magnetic sensor, etc...
The resistors come with the unit. Remember that you need 12 volts to power the Ocelot and any add-on modules (such as the SECU16I). You also need to run wiring for the Ocelot's data bus to the modules (I use a 22 gauge pair bundle).
Another thing to remember is the Ocelot also does IR (input and output) and can easily learn IR commands from remotes (has an on-board sensor that you press the learn button in CMax, then the remote button to learn). I use the Ocelot to switch a video matrix switch that has an IR remote control (actually it's pretty cool setup... I have my slingbox IR transmitter taped to the Ocelot IR input, then the Ocelot IR output emitter goes to the matrix switch. When I "switch" channels on my slingbox, it will switch inputs on the matrix switch). You will need an IR emitter to plug into the Ocelot's IR output jack.