I have 2, and they all live happily together with my yorkies
Chi's are AWESOME!!! Mine are sooooooooooo silly!!!
They wear a collar for identification, but for walks a harness would be what you'd want to use.
Mine eat Canidea. Both my yorkies and my chis. They all get the same treats too.
Chi's tend to shake all the time, but not nessasaly from being cold. Mine will even shake if is 90 - so I'd just judge it by if its really chilly or not.
Your going to love having one. Mine are the BEST!!!!!!!