Warranty starts from the day you purchase your camera from the authorized dealer. Whether you fill up your warranty or not, it doesn't matter. And yes, they have the ability to check if your warranty is valid just from the serial number of your camera. And no, your camera is currently not under warranty anymore.
For Canon, yes, the kit lens is registered separately. The body could have warranty extended for a fee, but not the lens. I registered online in Canon Digitalab at Harboutfront, out of convenience, when I bought it & went there to collect the Crumpler bag. There were 2 terminals set up there for this