Get down on the floor and sight down the chain, you will easily see if it is kinked. When it is arrow straight and with the correct tension, ride the bike and see how it feels. Measure the distances. If they are the same, you're good. If they are not, you have issues. It would also be worth loosening and then re-torquing the front wheel as per the book.
You can also use the ABS sensor to check the run out on the wheel just to eyeball it.
6mm is a lot of difference.