I was just about to mention the misinformation you've been given about the sunroof, but Adamsy beat me to it. Go down to your dealer and slap the salesman. What is it with those people? None of them ever seem to know half of what they're on about!
BTW, further to Adamsy's comment about being taken off the line, if you have the sunroof option the roof panel itself is actually an entirely different part made with the sunroof hole already in it, isn't it?
As for your towbar, yep, its a permanent fixture with the tongue poked through a hole in the bumper. Pictures below will give you the idea.
(image stolen from CarSales)
There are aftermarket removable products available, but they might be a bit pricey.
You can remove the tongue of your factory one, but you need an impact wrench, or really strong arms and decent spanners, coz those bolts are pretty damn tight! You'll end up with just the hole left in your bumper, and you'll have to cable-tie the wiring harness to something behind the bumper out of the way. Just remember that when you put it back on you do those bolts back up nice and tight - last thing you want is to see your trailer overtaking you coz the tongue came off.