2011 Ford Fusion. Replaced serpentine belt and now it shakes really bad when drove. Motor mount? Still starts and runs?

I have 2011 Ford Fusion. The serpentine belt broke while my husband was driving, going 75 on the interstate. He pulled over as soon as he noticed that it said it was overheating. He replaced the serpentine belt but when he put the car in drive, it shakes really bad. He first thought it was a broke motor mount but now we re not sure. It still starts and moves but we're leary about driving it. The check engine light is on and pulled up the following codes at Advanced Auto: p1299, p0625, p1285. Any help is appreciated. This is our family car.

Is this a good idea to get out of an upside down car Situation, please advice?

Long story short, without getting into details on how I got into it from the first place,
I have a 2018 mustang gt with 12500 miles ( which I about last Nov) , I still owe 43500$ , my payments are 677 a month, I'm trying to lower my car payment as I'm looking for a house right now, and this high car payment is not helping me find a house that I want!
I went to a ford dealership who offered 32k for my mustang ( which is A good trade value for my car According to blue jelly book) for a new 2018 Ford Fusion SE MSRP 26k they gave me about 9500 off MSRP and then added 11k for my negative equity plus tax plus plus ect. Total finance about would be 34k and my payment would be 480$ with good credit which I have. I'm trying to push this down to 32k total amount financed with 0 down.

Would that be a good deal? As I will be saving about 220 a month plus 50$ less from lowering my insurance, is it worth it, if I'm planning to keep the Ford Fusion for a while!

2010 Ford Fusion Gear Shifting Problems. I need

I was driving my ford for about an hour on the highway and after I got off and stopped at a light my car was still in drive but when i let go of the brake pedal the car started to roll backward. When i pushed the gas the car would rev but not move and no matter what gear i put it in the car wouldn't move. It would also randomly rev very high and the MPH gage would move as if i was driving. I then got my car towed to our local mechanic and he drove it and said he can't see anything wrong with the car. I then took it to a transmission shop and they said they couldn't find anything wrong and no codes were showing up but they can take out the transmission and check every part, but that is going to cost quite a lot.

I have seen videos and comments of people with this kind of problem and they are saying it's not the transmission, it's a Classic valve body (solenoid) failure or the mass air flow sensor. Has anyone had or know what this problem could be?

What kind of SUV should I buy?

I currently have a 2013 Ford Fusion that has given me an array of problems. We're wanting a mid-sized SUV, like a Hyundai Sante Fe Sport, Honda CR-V, Toyota RAV4 etc. I don't need high tech or fancy and can't afford the luxury kind. Just one that has good gas mileage, reliable for years to come, easy to drive and one that has clear sight lines. With my current car, I can barely see out of it simply to back up. Also, any suggestions can be a couple years old.