Is crowning short molars risky?

Not really: If they need the support you do it, you may need them redone later if the patient is young and has some growing to do. Crowns are meant to make the tooth more structurally sound, not jeopardize the tooth. Get a consult and a second opinion if needed.

Depends: This is a clinical decision made by your dentist, following some guidelines that your dentist is familiar with.