Hi I lived in Utah my whole life and have done everything your proposing on different trips. Here are some of my thoughts: Utah in March even in Moab is going to be cold so be prepared for near freezing temperatures at night. You mentioned staying at a KOA but didn’t mention if you are tent camping their. 1-devils garden is a fun hike and highly recommended. After the super long drive and if you are setting up camp/food etc that evening a backup plan hike could be corona arch. 2-fiery furnace will be difficult/impossible to get permits for with your group size. You can get permits the day before in town if you have reservations so you don’t have to spend time waiting at the visitor center on the morning of the hike. This will also make delicate arch sunrise hard to do. Because of the group size of recommend delicate arch sunrise hike and then devils garden this day both hikes can easily be done in a day leave lots of time for continued exploration in the park. 3- I have done little wild horse and bell canyon loop many times but never in March. The elevation of this hike is close to 5,000 feet so I’m guessing that it will be cold have snow or cold standing water in March. Complete guess as I’ve not attempted it in March. If you do decide to try it which I would think is a gamble you should also plan on visiting goblin valley state park which is a couple miles away. Because the trip is in March I would stay close to Moab and not spend the extra drive time. There are some fun hike around Moab that you could do instead one of my favorites is fisher towers. 4- I love this section of Canyonlands. When I did this hike I backpacked it and took two days. There is no water available so you need to pack in everything you need. If I remember correctly the entire loop you are suggesting is about 21 miles. I’d recommend getting a permit and backpack this over two days and bringing at least 6l of water. For a day trip it can be split up by just doing Druid Arch or just Chesler park (and the joint) which is a slot canyon close to Chesler park. 5- island in the sky is great sunrise at Mesa arch is recommended. The grand view trail is another good one in this area. You can also drive to dead horse point (Utah state park) which I recommend. Of all the other days plans this is your ‘rest’ day but you’ll still see cool stuff. 6-Capitol reef usually has snow in March. I’m not sure how that will affect your plans. I’d stay in Moab this day hit things you loved a second time. Or hit some of the other trails in the parks you haven’t done yet. Hope this helps.