[88Silver924S]

Re: "What are the risks of running this water pump for a while"?

When there is play in that bearing the seals will fail (leak) which will expose the "sealed" bearings to hot coolant which will wash out the lubricant which will cause the bearings to overheat from lack of lubrication and the bearing will seize or break-up, the balls crack and spall off pieces and the races gall; shortly, very shortly thereafter the belt is highly likely to break. With loose bearings the impeller may wobble and strike the engine block or sides of the pump cavity and break, jamming what remains of the impeller causing the roller to seize snapping the timing belt since it is a toothed pulley. If you are lucky the bearings will scream loudly and the stream of coolant out the weep hole will alert you before the whole Macgillicuddy lets loose.

Time to bite the bullet and change the pump.