It seems plenty strong for an inrunner like the Hacker. Just make sure to add the rear support. If you haven't mounted one before just search this forum for lots of examples. I did a Pinnacle build hear that shows one.
If you put in a Hacker you do not need either firewall so you can save weight there. The rear support will be lighter than the firewall.
The wire is to mount the rudder. The additional wood wrapped with teh wire. I have no clue yet

My wings are 401 and 414 gms. As far as total weight I haven't added it all up yet. I will try to do that later. The two CF formers with the cutout for the fuel tank also can be left out if going electric.
Stuart