>> 4. Try to apply Einstein's "synchronization" definition to more
>> than one frame.[...]
> 
> That definition cannot possibly be applied to clocks at rest in
> different frames.
 
Einstein disagrees with you -
"Also the definition of simultaneity can be given relative
to the train in exactly the same way as with respect to the
embankment."          http://www.bartleby.com/173/9.html