The Ms 250 can be a hard starter for a home owner. Especially when it's warm. If you choke it when it's already a tad warm you'll flood it. Not a big deal for a pro aborist.
The only way! I suppose vertical could work but I have no clue how you would even start . If it's not broke don't fix it ; applies well to your first question.
Seal your ends 2-3 times. Minwax sand & sealer works great. Getting harder to find the older stuff though. It's pricey but quality products should hold a premium!
For what you're wanting you might build your own cage for the hood and under carriage. Only thing I would suggest is putting hingable access doors in more then one spot. Repairs in field will go much smoother.