I drive my stock 2017 26fe at 70-75 mph all the time. I even pull a 7,000lb boat sometimes at 70. Wind is a huge factor. its a big sail so its going to catch some wind.
A alignment is a good thing to do if you can find a place to do it. If anything you will save your tires. Lots can be added to help and I will be adding those items as soon as I hit 3 years or 36k miles but otherwise mine drives very well. It is however Very different then a car and takes some getting used to.
I used to have a 2000 33' class A and my class c is like a sports car compared to that.
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