Rough idle, hesitation on acceleration, raw gas smell, rough running?

Now I have another question, totally unrelated to the vehicle and problem that I posted yesterday.
I have a 2003 Ford e-150 cargo van, 4.2 L engine. I'm having problems with what feels and seems like engine misfire. Plugs and wires all just got replaced, changed fuel filter and air filter, just had a fuel pump in December. There's a strong raw gas smell in the cabin while driving, and it is idling and accelerating really rough. Sometimes it will stall if I'm in D but stopped at a red light. There's some hesitation when I accelerate and loss of power and fuel economy. I was sure that it was the MAF sensor, and because I have tried cleaning it several times, and when I unplugged it there was no change in how the van runs, I decided to bite the bullet and replace it. So I replaced it today, and there's very little change in engine performance. There are no codes either. So I'm stuck at what it could be. Also will note that it idles fairly good when in park or neutral.

Take some Pepto-Bismol to get rid of those stomach symptoms you just mentioned.

When I replaced my spark plugs and wires in my 2006 Chevy Express van, I also disconnected the battery cable before starting it up. I was told to do that to make the van's computer/sensors recalibrate itself to the new spark plugs. My van ran absolutely horribly at first, but I drove it around for 5 minutes; and it worked great afterwards. I was totally shocked though at how bad it ran for the first minute or so after reconnecting the battery cable and starting it for the first time after new plugs. I figured driving it would solve the problem, and it did.

Check your fuel pressure. Possible pressure regulator has failed.

I think you have the ONLY Ford engine that I know of that has a MAF sensor. You know something about smelling gas, it is also visible, maybe you should take another look.

Time for a tune-up.

Mechanics are not sure about a MAF sensor being bad until they put a $2000 scan tool on the vehicle and read the engine data to monitor the MAF sensor voltages so how can you "be sure"?!
Have you inspected all the gas lines to see if one is leaking? What's the fuel pressure? Checked for a intake manifold vacuum leak yet? I could continue but there's no point. You have no clue.