2000 Ford 6.8 v-10 motorhome shakes and looses power above 50mps, can't go above 60mph. Looses power on hills?

Have a 2000 motorhome that has a Ford 6.8 V10 engine. On my way back from New Orleans we started losing power. I can get up to 50 miles per hour and it starts to shake I can get it up to 60 and that's as fast as i can get then it just slips and shakes real bad. The only way I can increase speed above 60 is going downhill and tapping the gas pedal increase speed otherwise going uphill I start to lose speed and can't accelerate without slipping and a lot of vibration. With the scan tool it said I had misfires on cylinder 2, 7 + 8. All spark plugs were changed and cylinder coils. Cylinder 2 still shows misfire and the problem has not changed at first I thought it was a transmission but now I'm not so sure

I bought an Actron CP9125 Code Reader to try and diagnose a rough idle at cold start on a 98 Ford 4.0 engine. The rough idle had not caused?

The CEL to come on. I plugged the code reader in with just the key on and pressed read and the little asterisk goes half-way across the screen one time and stops. I press the read button again and it reads 0 codes. I was thinking it would scan multiple times to check for pending codes or other issues. I tried it with the engine running and the same thing happens.
Is this code reader operating properly?

Truck heater giving off funny smell?

Have a 1990 Ford truck. When I use the heater it gives off a funny odor. It smells like a mix of old car that has been sitting and old oil. Any ideas on what it may be?

Can I turn a Pcp into a hire purchase?

I took out finance on a car that I love under a pcp scheme roughly 2 years ago. It has now reached its break even point and I thought it would be cool to get my monthly payments down and hopefully pay the rest of the balance off over a longer term so i can own the car at the end. Could I refinance £11,000 over a longer (4-5 years) period to pay roughly £200 a month? Or is this generally not allowed? This is with Ford.