1. As a way of making nitrate (required to produce hyperaccumulating fertilizer, ANFO and nickel hydrazine nitrate), you could process gunpowder (perhaps by reacting it or crushing it with a mechanical press) to produce potassium nitrate and sulfur.
2. Radium could be obtained from placing an old clock (obtained from a cleric villager) in a vat, radium wouldn't be that useful, however, you could use it to make nuclear pasta( A north Italian delicacy)
3. Toothpaste could be made from a plastic toothpaste thingy (whatever they're called) being filled with low concentration fluoride (the chemical, not potassium fluorite), toothpaste could be consumed(to give an achievement and nausea (and death:D(not really))), you could also use it to convert wither skeletons to normal skeletons (Because wither skeletons are obviously just skeletons with bad bone health)
4. A compat recipe for create crafts and additions where high-purity hydrogen peroxide could be mixed with blaze powder and lava to make rocket fuel, with could superheat a blaze burner with a straw for a relatively long time(30-70 mins)

Username: Redflox_

nice idea :D