10 years old is 10 years old. Who knows?
Yes the mileage is stored in the ECM and will be re-set with whatever cluster you bolt on it, "0" if new.
It would be impossible to hide all the damage from a salt water flood, but I doubt the fuel pump would be a victim. Probably just ran dry so many times from sitting, and re-starting, and sitting, and re-starting.
It's HELL on a bike to sit like that. Started with a half-dead battery, old gas, old acidic oil, revved in neutral while cold, overheating the charging system and filling the injectors with junk, dry seals, clutch clamped together for months or years at a time, old rubber, yikes