1)
Yeah, 皆客引きしていた shows that the actual subject is taxi drivers. In fact, as nekojita-san wrote in the thread linked above, 隣の家の前にタクシーがいる has a nuance that the engine is running, the driver is in the taxi and waiting the passenger. Furthermore, 空港には数百台のタクシーがあって sounds like the airport possesses hundreds of taxis to me.