Couple of questions about the current Civic
 

Hi, my wife and I are almost certainly buying a new Civic, but I have a
few questions that someone on here may be able to answer:

1) We've tested a DX-G, and we like it. We're wondering if there's
anything significantly different, besides cosmetics, between the DX-G
and the LX and/or EX? (I mean fit-and-finish quality levels rather
than obvious differences in installed features)

2) I've never purchased a brand new car in my life. Last time I know
someone who did so, they were advised to stick to city driving under
100 km/h until they reached 5000 km - this seems like standard burn in,
to get the engine settled (as you may have guessed, I'm pretty ignorant
about this stuff). Unfortunately our old car just gave up the ghost
and we've been planning a road trip and we're wondering if it would be
okay (maybe not advisable, but okay in general) to take our new car
onto the highway for extended periods of time?

Please feel free to add any other advice you may want to share with a
prospective first-time new car owner.

Thanks in advance for your time.