Eran,
I'm sorry I'm not able to help you with throttle linkage. For the past several years, I have gone strictly electric. I still love the sounds and smells that ICEs produce, but my age and health do not allow me to fiddle with them at the field anymore. So, my Beaver is powered by a RimFire .80 on a 6-cell, 6,000mAh battery.
I applaud you making the effort to post photos of your build. I agree that the instruction manual leaves something to be desired. I can clearly remember pausing my build to pull up the online version to magnify the pictures. And even then it was sometimes hard to figure out what was going on. Please carry on.
Again, sorry about not being able to assist with your throttle situation.
Take care,
Bren