You have that exactly backwards: a field of solar collectors is generally safer for birds and aircraft/spacecraft/PEOPLE than it is for a receiving station in the path of a 400MW microwave beam.
In the second place, "bird strikes" aren't exactly a common or even catastrophic problem for photovoltaics, considering they are more likely to be arranged horizontally and the birds have no reason to "strike" them in the first place. Solar-thermal setups may have a slightly different problem, but they're just as robust as rectenas would be.
So again, it's a wash. The advantages provided by orbital solar is MORE than offset by the disadvantage of it costing over a hundred times more.
It can't. Not in the amounts we're talking about.
Absolutely. But energy STORAGE is a different concept from energy PRODUCTION. Unless trickle-charging is a possibility, but then all you have is a giant orbital battery that occasionally discharges to customers as needed (and takes even longer to recharge). There are a lot of uses for such a thing, but commercial energy isn't one of them.
For the record: the single most expensive power plant on Earth -- actually, the most expensive ANYTHING on Earth -- will be the Hinkley nuclear power plant in the U.K., with a cost of $35 billion and will have an output of about 2GWe. The project YOU'RE proposing would cost close to a trillion dollars and would produce about 400MWe.
It's simply a bad idea.
