Re: stuck driveshaft
Yeah! This is a common problem. However, if you force it, the drive shaft will come out of the water pump. The problem is that the impeller drive pin will damage the water pump seal.
Once you get the lower unit off, then you can invert the engine and soak the driveshaft/crankshaft mating area with penetrant. Then, use a shaft collar locked tightly around the bottom of the driveshaft and hammer out the shaft.
Yeah, it is a bit of fuss and bother so be certain to coat the drive shaft and crankshaft splines with anti-seize to prevent it from happening again.