Hi and welcome Rox. yes, do fill the tires and yes, do add a seatbelt and use the rollover protection in its UP position. The rule is, no ROPS, no seat belt, ROPS, use seatbelt. For the reasons already mentioned. Jumping off a tractor with a roll bar on it at all could lead to serious injury or death, as the bar may be the culprit in keeping one from clearing out of the way. With the ROPS up, and a seatbelt on, there is a much better chance of avoiding injury. As already stated as well, it's better to go up and down hills, backing up to keep the front on the ground, and driving down forward, to keep the front on the ground! Check around with your neighbors to see how they are handling their hills, and maybe you'll get some ideas of what works best for them.
I wish you and your husband many happy years there and good health. John
I wish you and your husband many happy years there and good health. John