Mother of rough ridin' god I've learned to hate the drive you're taking (add on another 4 hours and you have my route back home). First of all,
don't go straight to i-35 on i-70.
go south on hwy 77 south out of junction city. keep going south until you hit florence, hit up the diner there.
keep going south till you hop on i-35 in el dorado.
This is only a good idea if you're not pressed for time. The fastest way to go is 177 through Council Grove down to Cassoday. I've seen a cop outside of CG, Strong City/Cottonwood Falls maybe once in the like 10 times I've driven that route, so you can usually fly whenever you're not in one of the towns. I do agree that going over to Salina and taking 135 is basically asking to hit yourself with a frying pan in the face. Entering Wichita from the north side would only be worth it if you were gonna get Spangles or Nu-Way with TheShocker, and seeing how he doesn't live in ICT anymore you might as well just enter it from the southeast (from the toll road) if you wanna stop off for some treats.
Scenery: Love the drive from Cottonwood Falls to Cassoday. Enjoy it while you have it, because any future scenery is close to nonexistent after you've passed the Flint Hills. You'll have a cute little 10-20 mile stretch through the Arbuckle "Mountains" in southern OK, which were actual mountains millions of years ago but are just big hills now. But that's about it. Traffic may be occasionally hairy in Oklahoma, particularly in OKC, and Norman is annoying in that they make you slow down for no particular reason. Then again, I try to get in and get out of that state as fast as I possibly can, so

. If you plan on stopping within an hour and a half of passing the last rest stop on the KS turnpike, then just stop at the last rest stop on the KS Turnpike. I mean, you might be able to take a piss at a gas station in Tonkawa or Blackwell, but the Bathroom Cleanliness Factor cannot be confirmed as being adequate for the standards of an elite like yourself. Guthrie--45ish min north of OKC--has decent gas stations/fast food restaurants, and I'm sure they have a decent cafe downtown or two, but downtown's kinda off the road a bit. OKDOT will close off lanes in the northern and southern parts of i-35 for "construction," except the construction likely got done around 6 months ago and they're just keeping a lane closed to make Texans and Kansans pop a blood vessel. FYI I blame OK_Cat for everything wrong about Oklahoma, which is everything. There is some place advertising fried pies in southern OK, so if you're looking to try some of the local fare you could always check that out I guess. Ardmore is somewhat unterrible. Prairie Kitchen is also somewhat unterrible.
Staying with traffic, you will run into an unending hellscape of bad drivers in Gainesville--more accurately, 20000000000 rough ridin' cars will magically appear on the road like holograms as soon as you pass the Winstar casino exit right before the Rio Grande. As a Texan, I can say that we are proud of how rough ridin' terrible we drive and have probably made an unofficial sport of it that we can't really confirm or deny to outsiders. Try not to die, plz. Downtown Gainesville might be worth stopping in, especially if there's a Whataburger nearby. They also have outlets near 35 if that's your thing. Don't have any specific cafe recommendos tho, sorry

Denton is a clusterfuck to navigate from 35, so I wouldn't stop off there unless you were just absolutely dying to go see TheTastyGreek.
Unless you have a specific destination in Dallas to go to, avoid 35E like squawks avoid anywhere outside of Johnson County (OH LOOK TOPICAL HUMOR). Downtown Fort Worth is actually pretty nice--spent most of my time in it in kind of a haze but there are some good places if you just kind of explore. You'll either get shot in downtown Dallas (no sarcasm) or shoot yourself from boredom. I did stumble into this relatively expensive but very cool place called the Trammel and Margeret Crow Asian Art Museum in downtown Dallas once. Like, I don't give two flying shits about art, but there is some very, very interesting stuff in there. But unless you're gonna go see AMERICA'S BASKETBALL AND HOCKEY TEAMS play at the

center, that's like the only thing really worth checking out in downtown Dallas. Plano/Richardson is basically three building templates copy/pasted into a giant rough ridin' area (sorry BigDCat if you're from there). Highland Park is where you go to feel completely inadequate about yourself. South Dallas supposedly is where everyone gets shot and carjacked, so there's probably tons of cool crap there that nobody knows about. Arlington is only worth it for Six Flags, and I don't think it's open this time of year.
Anyway, the best way to spend this drive if at all humanly possible is not at the wheel and passed out. But, hey, BigDCat can probably offer a much less jaded perspective than mine and be much more informative about DFW and local Denton/Gainesville fare.