Road shoes are fine for the trail section. Most of it is crushed gravel. A couple of sections may have a few small larger than gravel size pebbles, but still nothing like real rocks at all.
No spectators on vast majority of the course. There's a good amount of shade inside the state park. Once you come out of the park though until about Mile 21 there isn't going to be much shade at all. The sun will be kind of behind you/to the side from about 11 to 14, but once you turnaround at 14, its a good stretch where the sun is going to be directly overhead and you'll be mostly running into it. You'll have spectators at the beginning first 2 miles or so, 18 to 20 and then again from 24 to the finish. Not a lot though but they are a good crowd and will cheer for everyone and not just "their" runner
There's *MAYBE* 200 feet of total elevation on the course. A quick google search shows 272, but I'd be surprised if it was even that. There's a section from like Mile 10 to like maybe 10.75 that maybe has 100 feet of climbing. Theres like 3 or 4 very small maybe 5 to 10 foot hills in there around one of the towers. They are in quick succession. Then there is the bridge at like 16.25 or so that is maybe 50 feet. Once you get over that there literally isn't another hill on the course, save for like a 3 foot one on the trail somewhere (can't remember where this is...mile 23ish?)
Weather looks okay. Low 50s at start. Low to mid 60s. High of the day isn't supposed to be like 3pm. Be prepared for some wind. Always windy in Delaware March thru May. Expect 10 to 15mph winds. In the park and from 21-23 you won't feel it much at all though.
The 'thon is pretty small. If your shooting for a faster time, my guess is you won't have much company and will be alone for vast stretches. Looks like in 2023, they had 15 total under 3 hours. 73 under 3:30. This is out of 624 total finishers.
I might come down and hang out as I've got a decent number of friends that run it. It's a nice course.
If you have family coming down to watch you, it's NOT the easiest course to get around. I can get them around pretty easily, but it takes some planning. If this is the case, just let me know. Parking is tough. Half has about 1200 runners. There isn't any parking garages, nor is there really any big parking lots. It's basically neighborhood parking around the start/finish area. If you arrive REALLY early (lets be honest, the 3 hour half marathoner will be the ones doing this), you can easily get a spot on the "main drag". All parking is free, no meters, just don't park in a businesses parking lot, they do tow.
If you can't find a porta pot easily, there is open public restrooms on Rehobeth Ave right behind the "main" gazebo near the start/finish line on the boardwalk. Can't miss it. It's in the center island.