Transport routes generally are highly centralised.
Shipping traffic is a case in point. Nothing keeps a ship from travelling anywhere over the oceans ... except that ports and profits are in specific locations. Traffic denssities are high enough that you can track major shipping routes by their sulfur-dioxide emissions on satellite atmosphere visualisations.
Probably Not as most commercial flights follow pre-determined corridors. So while it would work for those corridors I think most of the land masses are never hit.
Add to that that these flights were probably done from much lower altitude than regular commercial flights operate at
Reflecting a laser from earth all the way back to space is hard. The recently launched NASA satellite to look at the extent of polar ice fires a laser at earth and looks at the reflection. Ice is reasonably reflective yet even then the satellite gets about 1 photon back for every 1e12 it sends out.
Firing a large laser is expensive in terms of energy and expensive in terms of temperature: once a satellite is hot, it is not very easy to call down. All you can do is try to radiate the heat away but that’s not so easy or effective.
