ours love tyres - just asked for ours back when the car had new ones!
the boys play football ... really! One that is abit flat is better, it doesn't bounce too much and our Cesar can scoop it up with his horns or carry it round in his mouth!
paper food sacks - leave a little bit of grub in the bottom. just dont leave them alone, as they can get them over their heads & panic!
We find that "new" things can be treated with suspicion ... then get played with ... then get left, so change things round a bit. (but gently!)
Tree branches - willow especially; once they've stripped the bark, change them.
Hope the "Home visit" went well HK, how long til you get them?