You can't do any service on the machine, even techs have to have a usb key that headquarters generates for your call. Techs can't go "rouge" (the printer is connected to Canon servers, not required but recommended for quicker tech service as they can remotely diagnose machine)
First year of owning the machine I did not have a service contract and all service calls were covered with the 1 year warranty (printheads excluded in the USA). Now I signed a service contract, the overall service contract price will be the same no matter if you sign up on first day of owning the machine or a year later, better signup on day 1 and lock in price. On day 1 there was a 5 year contract option available, a year later I was only offered up to 3 year contract. Wish I signed up on day 1
The print area is fully enclosed and there are charcoal filters that filter the air coming from the machine, no misting.
There is definitely a smell, some materials/speeds worse than others. I installed an air scrubber and good ventilation
The cost of machine/service contract you can get pretty easily by contacting Canon, that's the only price that matters not what someone else paid. You can expect the prices to be 3-4x higher than an Epson etc but when you account for how much you save on ink the Colorado is cheap if kept busy