I just installed one on mine wednesday and i had the same issues you did.
The seal around the maf seems larger then the hole, i might have a vac leak now. I had to pull the fender shield out just to get the filter on after i slid the pipe down into position. Las was the fitment of the intake to the throttle body. I think i had to clamp mine down to the smaller tube size.
I think the problem there is the intake is for "2.0 and 2.3" duratecs maybe the 2.3 duratec has a larger throttle body?
I had another issues you didnt mention. The breather line for the engine block. The stock setup had a plastic line from the back side of the valve cover around to the flexable boot connecting to the airbox. This intake just has a little section of hose.
My hope was to get rid of that setup all together. Using a seperate engine filter or a better line or something other then that plastic pre shaped line
I guess now days you cant expect much for $200.