Have fun! Oh, and I misread your post and though your were adding step ups to squats...probalby because I shifted the adding pullthoughs onto the first sentence somehow. Sorry about that.
Foam rollers are great. I use a foam roller and I can't say enough good things about that. It is not a cure for any underlying pathologies but it works out the kinks and helps resolve tight spots and trigger points and can definitely help keep you healthy. You can use it for certain stretches an mobility work....it is cheap and worth every penny. I LOVE my foam roller
Keep up the good work and keep up the thinking, experimenting....