Yes, Outbound Loadbalancing is set up by default on our devices and this applies to a time when traffic goes out to the outside world.
(Please know that Peplink is a session based load balancer, so when a session is established from LAN to WAN, this session keeps utilizing the same WAN until a new session is created.)
Yes, you would want to have a static IP for Inbound Loadbalancing. Please refer to the following KB article.