I think you've missed the point(s)
100 mile difference isn't a big deal, but the cost of tolls isn't really that much either. That's the point. Those extra 100 miles mean you're going to spend around another $15-20 in gas, and considering the tolls in IL, IN, and OH aren't much more than $20, you don't really save anything by avoiding the tolls. (By taking the "central" route, you're actually adding a couple hundred more miles, so you'll actually spend more than by taking toll roads, plus it looks like you're still planning to take the PA turnpike instead of cutting north in Ohio like I suggested, so you'll be seeing significant tolls anyway.)
An EZ-Pass doesn't really expire, you just need to have money in your account.
I'm not sure what you're trying to get at about the weather, but you continue to be very misguided in assuming conditions in Wyoming will be different or better than Montana. The average low temperature in Bozeman in April is 30 degrees. The average April low temperature in Rock Springs, Wyoming - along I-80/your central route - is 28, two degrees colder.
I don't know what you mean when you're asking about "table tops" so you're going to have to explain if you'd like an answer. If you're talking about flat, high elevation areas, that's pretty much describes the entire drive across Wyoming.
And finally, the stopping points you've listed are still too far apart. Your current plan has you driving nearly 700 miles every day, except your last one, which is not a safe or sustainable pace. You need to shave about 100 miles off of each of them and plan on your last day being a full day on the road, not a half day.