Yes, that's correct. Theoretically any of the bikes sold after that will have come from the factory with the firmware updates so shouldn't have any of the problems previous motors
might have had. The extended warranty is really a good will gesture just to put existing owners minds at ease. I don't think they extended it for the 1.3 bikes as they didn't have the same issue as the 2.1 bikes - would have been nice though
If you've not had an emtb before it will be difficult for you to pick up on anything which is wrong. Even if there is, it might only show up in certain circumstances. For whatever reasons some motors are slightly noisier than others - if it's making any really horrible sounds though - it's probably got something wrong with it.
If he has the bike connected to Mission control - Specialised software for android/iphone - he can show you the mileage. You'll also be able to see battery charge - ie, 100% for full .. battery health - what % of the original battery charge the battery can now hold. It might be 90% for instance.
You'll also be able to see charge cycles. So on something like a Kenevo, that might be 100 charges for 1500 miles if he got 15 miles a charge on average. That's not necessarily how many times he's charged it, it's how many full cycles of charge the battery has been full. So if he used 20% 5 times, that would be 1 charge cycle - no matter how many times he charged it in those 5 times. It might be a lot less, but quite often Kenevo's will be used to climb so you'll use more power. If he's got 200 charge cycles for 1500 miles, I'd be suspicious of the distance, unless the battery health is really low or he rides only in Turbo and up very steep hills at a low cadence.
If it's just been charged, when you turn it on, it will probably be in Turbo by default. So press the "-" button twice before you ride it. So it's in Eco .. you can press it 10 times if you like, once it's in eco it won't beep anymore and won't go any lower than eco. If it's not just been charged, it will be in whatever mode it was last used in.