Hi again,
So you went for a breeder in the end?
I can’t think that there are any toys that would put rabbits at risk of illness…
There’s lots of ideas for toys in the habitat and toy section take a look: https://binkybunny.com/FORUM/tabid/54/aft/107056/Default.aspx
Cardboard boxes are the best toys by far in my opinion and yes they are safe (and FREE, yay!). If you’re concerned, use a plain brown cardboard box, (ie. not one with coloured packaging) although I think even those are fine. The buns will chew them and rip them but usually not actually ingest much of it.
As for the hay, as you sound like you know, hay should be the main part of your bun’s diet. Lots of rabbits aren’t fantastic at eating their hay though (I guess it’s like many people don’t love having their veggies, even though they should). You could try different varieties of hay to see which your bun likes best, I think orchard grass is very popular.