CARP + QOS Setup solution

[alexus]

Ok, hi all
I decided to play around with failover and loading and balancing.
I looked at the docs and found 2 resources talking about redundant router installation and dual wan. But I have a bit different situation and I’m not sure how I can implement CARP. So I attached the image to show my network setup (I can’t really change the network setup)

So, Segments #1 and 2 have access to dedicated WAN lines. They both run Captive portal on LAN interface, and also there is wireless bridge that connects them together. We could of put bridge on dedicated interface but the problem comes with Segment #3 where we do not have pfSense installed. The locations such as Segment #3 are homes there we have only Wireless CPE (Bridge that connects directly to client computer)

Well I thing I’m getting lost now so let’s go to the question:
I wanty traffic between Segment 1 and 2 to be loaded and balanced + is one WAN line on any segment dies we would automatically switch all users from the segment with dead line, over the wireless bridge to the segment that still operational. Also at the same time users on Segment #3 should be able to access WAN network via same Wireless bridge. I suspect that loading and balancing for Segment 3 users is impossible unless we install pfSense box there, but I think failover should work since bridge is central for all segments. Also my concern is the CP operations.

Well can some one help me here? I'm new to CARP thing and not really sure what should i do.
Thanks!