Hi, I will be keeping an eye on your post. I have researched loads of different ideas as well as having a Kyham Motordome that is ok but gets bad reviews in windy weather and is a bit of a pain to attach to the van. My latest thought is to go with a Quencha seconds base as seen in some of the threads. They are now though discontinued but you can get them from ebay, and have a tent / shelter which is what I really need rather than sleeping and to not attach to the van. A few people have written about getting up in the night to detach flapping tents, and also my motordome left some rub marks either end of the van where the elastic seals the gaps.
I would watch out for that as it took a lot of T cutting to get the scratches out. Have looked at the tent you bought and a minor prob with mine as well as yours is that you cannot have the front guys pointing forward for stability to keep the front porch up without the van being too near.
We have the outdoor revolution drive away awning as it came with a sewn in groundsheet and the Kyham one didn't at the time. The Riemo multirail is very good and secures it very well. You will get the edges of the tunnel rubbing on the van if you peg the sides down touching the van, but at night we leave the tunnel attached but peg the bottom of the tunnel back to the bottom of the tent so it doesn't rub.
I was thinking on the same lines as you to peg back the elasticated sides. I am surprised no one has mentioned the problem of damaged paint previously or maybe I have missed that thread. I have seen loads of photos with ropes, guys and all sorts going over the roof and down the other side of the van and wondered if there was any paint left on after a windy weekend.
awnings - I got a TARP from decathlon for £20. It's like an upside down V shaped nylon waterproof shelter with 2 poles and guy lines and pegs. I got 4 taxi sign magnets (heavy duty rubberised magnets) from ebay to hold it onto the roof so it all packs away when not used.
The thing about the shelter is you can put it up in different arrangements with the poles. Usually goes up flat as a rectangle from the van roof with the two poles at the 2 corners furthest from the van. guy lines hold it well.
Or, if it rains (eg at night), you can just drop the poles and the awning is sloping down towards the ground from the van roof, or just drop one corner down. Or, you can put it up independent of the van as a shelter type arrangement. Very cool.
I have an outdoor rev. 2+2 awning tent which I think I might sell this year as I'm not using it (used it twice all of last year!).
It's two bedrooms, and its length goes alongside the van rather than away perpendicular from the van so uses less space for pitching. Very good design and to be honest haven't seen that layout elsewhere.
The two bedrooms are divided along that length by the central open area which would line up with the sliding door. Excellent awning tent. Would probably sell for £120 - £150 on ebay, and have spare poles aswell.