Cog looks right to me. The stock cog on the Track has a big lip on it that would be very evident in either of those photos. It looks like the angle of the picture is what makes it look like the chain is rubbing the sp0ks.
The stock BD cogs suck, but they'll do their job for a decent set of miles. Only change it if you are OCD, it wears out, or you need to change your gearing.
A good lockring isn't that expensive. A $10 investment now might save you many times that amount when it prevents you from stripping your hub threads.