Moving fancy mice enclosures?

I've had eight female fancy mice for a week now, and they've already become quite trusting and always come over when someone reaches into their cage. I'd like to change their environment because I don't want them to get bored too quickly. Would it be okay, for example, if I moved one object every day (obviously not the sleeping house or the water bowl for orientation), or is that too often?

And one more question: they don't use their balance bike at all. It has a diameter of 28 cm and a cork tread. Is it bad if they don't use it or should I do something about it?
This is the enclosure:

Should I change anything else or is it fine like this?
I'm happy about every answer 🤗