Looks great. I would not worry about the lack of roof vents. They base it off the size of your trailer. So since your trailer is smaller it only has one vent. With your vent fan on and a window open, you will get a great breeze coming from the window. Your fan will become an exhaust fan, bringing fresh air from the outside in.
Good luck camping and have a blast.
Philip, DW, 3 DD, 1 DS, and Kadie our Dog
2013 Flagstaff V-Lite 30WTBS
2003 Ford Expedition 5.4 Liter with 3.73 Axle
Equalizer 4-Point Sway 12000# & Tekonsha P3
48 Days of Camping Reserved for 2012