I am using a Peplink Balance 30 router. Right now I have only one public IP. I have set up the LAN for 192.168.8.1. I have five devices on the LAN side, including two Ubiquiti Rockets and three IP cameras. My question is: Should I be using NAT with only one public IP address? I have configured port forwarding rules and am using high-numbered ports to access port 80 for management of the devices on the LAN side. For example publicIP:55000 is port forwarded to 192.168.8.2:80, etc.... What is the best practice to do what I want to do?
... set up the LAN for 192.168.8.1 ... Should I be using NAT with only one public IP address?
If your devices require Internet access with IP4 you need to use source NAT/NAPT. Destination NAT is required when you need to provide access from public addresses to private addresses inside your network.
The best way to use NAT is to avoid it wherever you can. NAT is a crude kludge, breaks various things and is at its best when it's absent. For communicating between private networks, VPN is the best choice.
A VPN tunnel not only allows transparent addressing between the networks, without mapping between public and private addresses, it also provides encryption. That way, no sensible data can be overheard from the outside (maangement/user credentials, etc).
Note that for devices to be on topic here, the vendor needs to offer optional, paid support.
With only a single public IP address on the internet service, and the desire to use more than 1 device on the network that uses that internet service, you MUST use NAT to share the single public IP address for multiple devices.
As for providing remote access to manage the devices on the LAN inside the router, you can either do port forwarding as you describe or simply use VPN service to be able to connect a VPN session to the router which would be configured to allow access to whatever devices you want on the inside LAN.