I've driven my E-450 mobile home only a handful of times in the last year, and it's developed a couple problems. I have only a few repair projects under my belt, still very much a Youtube DIY mechanic, so I'm hoping somebody can point me in the right direction or enlighten me if there's something uniting all the symptoms or some line of inquiry I've not considered.

1. It hesitates when starting, and surges when idling. The lights inside the cab will even dim as the engine putters along, deciding whether or not to stall out completely or come to life. It stalls about 30% of the time, it's worse when it's cold. If it makes it past the first 10 seconds, it runs alright, but the RPM's will start to surge when idling, sounding very inconsistent. It thus far has not stalled while driving it. The spark plugs haven't been changed in 2 or more years, (I've heard this can be a nightmare to do on the Triton v10)

2. For the first 5 minutes of running, the exhaust from the tailpipe is very excessive, and very white. It smells bad and causes a headache. About midship, in front of the catalytic converter, there is an exhaust leak that is white, with maybe a slight tinge of blue in certain lights. But more white than anything. Out on the road, the smoke eventually runs clear. (So perhaps valve stem oil seals are bad too?)

3. The Evaporative Emissions system has been disconnected entirely by someone who previously worked on it. Perhaps this contribute to the above mentioned issues?

4. The gasoline inside the tank is apparently rusty and gives the gasoline an orange tint. My mechanic advised me to change the Fuel Filter every 500 miles. A week ago was the 500 mile anniversary, so I did that. To relieve fuel pressure I pulled the Fuel Pump Relay fuse under the hood while it was running, (the top left fuse, big block), and the engine kept running. I eventually shut it off after about 20 seconds, not sure why it wasn't running out of fuel by that point and worried something was wrong. So I just pulled the fuel filter off without relieving pressure and caught the extra fuel with a towel. (So maybe there's something wrong with the Fuel Pump Relay fuse as well?)

Does it sound like multiple issues, or just one central concern that I'm missing?