Shower pump bearings going - risk of a leak?
The failure mode on a shower pump should be that it simply stops working if the bearings go, ie grind to a halt or just not turn on. There should be safeties that prevent overheating and it is unlikely it will leak. However, unlikely is not a guarantee nothing bad will happen, and if you know it's going I'd take action to fix it or replace it before you have a chance to find out.