Hi:
Not sure if US is different, but in Canada the Driver Entry Package is optional on both SEL and the Limited. I am assuming your question is not what the differences in standard equipment are, but what isn't available even as an option on the SEL. No guarantee of perfect accuracy here, but I think the items you can only get in the Limited are the memory seats, Sony radio, backup camera, garage door opener and also access to a number of options (e.g. 20" wheels, adaptive cruise, HID headlights, etc.). The trim is different on the Limited too (black interior console, wood trim on dash etc.). We went with the Limited because of the memory seats and the backup camera which were important to us. My wife and I couldn't have more different driving positions, and the rear window view isn't the greatest IMHO.
Yes you can add the accessories to the roof rails later.
We ordered the Earth metallic - yes we like it! Colour is a personal choice, of course.
Looking forward to getting it. Hope that helps you.