First question, if you are using PTP radios, yes. (There might be slight oddities if you use PTMP because multicast isn’t supported, but that would be dependent on your OSPF setup.)
Second question, the radios will need IPs for their management. So, as long as you don’t need to remotely access the radios you can use whatever doesn’t overlap with your current network. That said, if you want to remotely access the radios there are a couple options, most people use a /29 between their routers and assign the radios IPs from that space. Then you decide which of the routers will the the gateway for each device and you will be mostly set.
As far as cloud management, you would need to give the radios Internet access in one way or another.