If you could take Gus to a smaller area, like a bathroom, or maybe your porch if it isn't too big, or inside an xpen, then sit with him and just let hm hop around and explore. Don't even try to pet or touch him unless he comes up to you and seems very interested in you, then you could let him smell your hand, and even try and pet him if he seems ok with your hand near him. Doing it in a smaller area with no hiding places, makes it so that he has to get used to you being there, since he can't just go and hideout somewhere.
Picking him up is just something that he'll have to get used to, since it's a necessary thing. You can try different ways of doing it, or holding him, that he seems the most comfortable with, but every rabbit is different in which ways of holding they feel most comfortable with. My really wiggly ones I'll hold firmly against me so they can't wiggle and accidently squirm free. I will even hold my hand over their eyes to help calm them down, if I need to.
Well, since your boys are bound and determined to be with each other, and seem ok except for some humping, you may be able to try a play date with them, maybe on the porch or outside. I let some of my boys play together. They're brothers, so they are used to each other, and get along pretty well, but they do less humping and get along better when I give them more space to hop around. Inside they just run around and try and hump each other, so I don't let them play together inside anymore, but outside they are too busy exploring to bother much with the humping. So since your two have already been together and haven't killed each other, playdates may work out fine for them. You could try one and see how it goes. If all they want to do is hump each other, then there's not much sense in doing another playdate, and you'd be better off waiting a few more weeks for the hormones to subside. But with tucker being nervous about the porch, it might help them bond a little to be there together, and may help Tucker feel more comfortable being there, with Gus near.