So my question is how can i balance inbound traffic on 1 pc across all 3 wan lines Thanks 
Your sessions should be spread out on all WAN links. What do we have under outbound policy?
not worried about outbound just inbound… so it should be fine?
And on a side note i was noticing the main pc i work with gets a different IP every now and then is that due to peplink? Cause im using 3 different modems?
Yes for BitTorrent it is fine. Peplink will spread your peer connections across your WAN.
The LAN IP should be dynamically assigned by Peplink DHCP server. This is normal. Nothing to worry about.