UniChris

I can really only comment on Easton to Morrisville/Trenton along the Delaware and its canals if you chose to go that way, which I don't know if you will.

Through much of the Delaware portion you have options on both sides, often the PA side is more scenic and the NJ faster going. Some of the paths are really nice, some can be a bit soggy at times. There are frequent bridges back and forth but they are all walk-only. Could also often see people riding the road on NJ side rather than either towpath, and you're clearly going to be doing that a lot in other sections; the roads on the PA side looked narrower.

Between Easton and Uhlerstown/Frenchtown there's not much (at least on the PA side, which is the only one with a towpath in that section) - a gas station somewhere in Rieglsville but few other options to resupply. Frenchtown, New Hope, Lambertville, etc are very pricey tourist spots and even if you decide you're willing to pay, on a nice day you may get absurd wait times for food. The former train station at Stockton isn't terrible for price or wait, and I finally found a cheap bodega on the south side a block back from the water in New Hope. It could be worth the detour to the actual grocery store in Frenchtown. You may want to adjust the overnight depending on what you can find - there was an airbnb in Kintnersville I considered before refactoring the trip, but generally its a pricey area for lodging.

There is a spillway around Riegelsville which sometimes has an inch or two of water on it; when I rode in March the canal was basically empty but that's something you can check.

Also beware Easton is on top of a mountain, and much of it very car-centric design, sounds like you're not really stopping there so try to just skirt it.

A few of the bridges over the PA side towpath are too low to ride under. Many have sharply carved water channels in their red clay, hiding in the shade of the bridge.

If riding south on the NJ side towpath between Stockton and Lambertville, be sure not to miss the dogleg under the RT202 bridge, otherwise you end up on an abandoned rail ROW that gets steadily worse and worse, rather than the path which is fine. The dogleg crosses residual tracks; the east side of which is embedded in the surface but the west side of the west rail is exposed, an unexpected drop that nearly spilled me.

In terms of things to see, the little tourist towns are cute. The bridge at Bull's Island is unique. On the PA side opposite Stockton you can see some disused canal boats for tourist rides mired in the mud. New hope shows bits of the canal history but the towpath isn't really usable south of the bridge until after the locks and detour back out to the rive. There's a neat mill complex just north of Lambertville. Washington Crossing is worth a quick look-see as an outdoor museum. And the PA side generally has a number of picturesque estates and buildings fronting the canal.

Even if you're planning mostly to use roads, if you go near the Delaware try to do a few miles on each towpath just for the experience.