Again, that would constantly accelerate the front craft away from the following craft. It would require ever-increasing precision in aiming the front craft's beam or positioning the following craft, and would result in an ever-decreasing received beam strength.
It wouldn't take long.
I strongly doubt that. What is your source?
I suspect that when the numbers are all added up, this Rube Goldberg scheme will be shown not to work. But, I could be wrong. In any case, we're a long way from your "duh," which I hope was a joke.
The physicists who worked all this stuff out are my sources. Dunno at this point who they were, nor do I care. Your only source is yourself. But obviously this subthread is far more important to you than to me.