I have certainly heard that Aluminum forks fail although I have never seen one fail (I currently have one and those pictures give me the willies). I would say that the fork is certainly done for and should not be ridden. I don't really know if there is any feasible way to weld the fork but being aluminum I would say no.

I have heard that 26 inch forks should work with that. I mean there is always a chance of jimmying the wheel into a different fork but I have no experience with that and don't want to lead you wrong there. But perhaps finding a fork with a similar sizing to the wheel and then either dealing with some long-reach calipers or the like would help. Might want to check an online parts site like Nashbar or Performance.