Perhaps we could provide more help if you just came right out and told us what you're you're trying to do. i.e., what is the end goal here? In other words, I don't know how/why you're trying to open the xml in Excel, or how you expect it to work. If all you want is the distance and elevation, then Excel would be the last thing I'd try.
There is no elevation information because Garmin calculates the elevation plot when displaying the course. It is not part of the data. You need to feed the input data into something to determine the elevation at each point so you can estimate the elevation gain/loss. The distance of the entire course is the sum of the <DistanceMeters> values nested inside <Lap> elements. In this case there is one lap element, and the distance is 89880.72m.
I'd suggest using some other service for this. If you must use courses from Garmin Connect, that's fine, but I'd upload the course data to some other service to get the information you seem to be looking for.
I am also very interested in exporting courses created in GC to TCX files. The reason why I would like to do this is that sending the course directly to my (FR305) device does not work for me. Sending the course to the device did work a few times, but the last time I tried this it crashed the course memory on my device! I then had to erase all data on the device (hard reset) to resolve the memory corruption. The other problem that I found is that when you run a course that you have sent directly to the device using GC, the Virtual Partner page gives you erratic data. Somehow the distance numbers in the track points seem to be wrong. I have already posted this on the forum. So exporting courses to TCX is important. The alternative being using other web based software, such as GPSies or MapMyRun in combination with GPSies to convert GPX data to TCX, and then send this file to the device (via good old GTC!).
As far as using TCX data in Excel I can add the following. Since the speed graphs shown both in GTC and GC are virtually useless, due to the spikeness of these graphs even if you ran at a constant speed, there is a good reason for exporting the data e.g. to Excel so you could apply formula's on the raw data to produce "smoothed" data, that you could then use in speed versus time plots.
Also I saw on the internet that the distance number in the track data don't match with the distance in the trackpoints. This is apparently due to the fact that when you use smart recording, the device seems to add the distances travelled at 1 second intervals and records the accumulated distance when creating a new track point (about once every 7 seconds) instead of computing the distance between the two track points recorded. So you could let the Excel spreadsheet compute the real distance. In fact, I have written an XSLT style sheet that creates an Excel worksheet for every activity contained in a (huge) TCX file. I also let the Excel worksheet compute the distance between each pair of track points. This shows that the computed distance matches the recorded distance to a great extend in lots of track points, but occasionally there is a remarkable difference.
Another very good reason for using Excel is the fact that the device sometimes records running speeds in excess of 100 mph (in tunnels). In Excel you could eliminate these erroneous points! In other words there is a lot of work to be done for Garmin to collect correct data on the devices and to present useful data in e.g. GC. The software has to take into consideration the GPS data is accurate to approximately 3 to 4 meters (at most), so if you compute speeds on distances that may be off a couple of meters, the speed numbers may have errors in the order of 10% or more. Speed graphs with this accuracy are virtually useless.
