I normally leave my ladders hanging over the rear roller, so I would say yes they should take splayed feet.
The vivaro as a payload of 1023kg, It won van of the year when it came out and is very highly rated. I spoke to my uncle at weekend who goes to Spain for 6 months every winter towing his caravan. He was that impressed when he test drove the van he got rid of his car and bought the van just for caravaning, the drive is that good in them.
So how come I have a Fiat Ducato? One reason Is Its payload is 1145kg, so instead of a 650 tank which I was originally aiming for, I have been able to put in a 800ltr tank which works great. My son works with me sometimes so we have never run out of water, though we have come very close at times. A 650ltr tank would mean I would have to refill.
The other reason is cost. The Ducato as more room. I carry inside the van up to 7 poles plus all my trad w/c stuff and I still have loads of room. I bought my van for cash on the internet brand new, it was up to £3000.00 cheaper then a vivaro and better equipped.
My advice buy the biggest Van with the best payload you can afford. Dont just think of what you want now, but think of what you might need in three years time depending on the plans you have your buisness.
Nel.