When using larger tires (gravel and mountain bike) at lower pressures, hookless rims offer a higher durability and better protection against rim damage from impacts
Whether you are racing gravel and want to mid depth of the Pinnacle wheels, or of you want the ultra-lightweight and wider Jocassee there's a gravel option for you
No, although for gravel riding going tubeless is a huge advantage. However, since your tire pressures will be lower than on the road you can still run a non-tubeless tire and inner tube. You will have a much better chance of getting a flat tire though!
The Pinnacle is great for faster speed gravel riding on flatter terrain (think racing Unbound or another gravel race). If you are looking to put 42mm and up tires then the Jocassees definitely have an advantage due to the wider rim profile.