Hmmm. Well, the first thing I notice about the recipe is the absence of specialty grains. Back when I was doing extract batches, I always used a minimum of a pound or two of specialty grains. What you'll get will certainly be beer, but I'm afraid that just using trappist yeast won't make it taste like a trappist dubbel. Next time you do an extract batch, you should steep a pound or two of specialty grains in the water (@ 150f for 30 mins) prior to the boil (be sure to remove all grains before boiling). This will impart the flavor you're looking for without having to mash. I've never tasted or made an extract-only batch without specialty grains steeped in it, so I'm not sure what your final product will be like. But you won't get any roasty or malty characteristics. And your color, well, this is going to be more like a tripel, given that you used all x-lite extract. A dubbel is brown, this will be golden, as nothing in that recipe has much of an SRM value. If I were you, next time, I'd steep belgian aromatic and special B malts.
Other than that, you seem to be on track. Given the high alcohol, I'd keep it in secondary for a month or more, then bottle. You were right to leave the sediment (trub) behind. The alcohol smell/taste will lessen with time, but it'll always be a pretty alcoholic brew, especially given that there are no malt/roast characteristics to balance it out, nor is the IBU value too substantial, so the alcohol will always be dominant.
What I'd suggest to you in the future is, either find recipes online, or buy ProMash or another program so you can formulate your own recipes. Like I said, what you've made is certainly beer, and it'll definitely be drinkable, maybe even great...but alot could be improved upon next time. Good luck!