As you surmised a leak is not normal on any new part installed, the fact it stopped would indicate another problem, slave can't "self seal" itself.
Never seen a clutch push rod break.
The hose from master to slave has a "quick disconnect" fitting at the slave, these can come loose and that would "lock" the master since the fluid would have no where to go when you tried pushing the pedal down, that hose is sealed when disconnected.
If that happened and you pushed VERY hard on the pedal then maybe you could break the push rod, maybe.
Don't really see any way around it, leaky slave and broken push rod means dropping the trans and replace parts.
You could sell it as is, mechanics special