I don't get the tourism argument. Many countries do very well without royalty bringing in tourism. If she wasn't living in the palace there could be a charge year round to pay for maintenance (and tourists would still flock to see it anyway). The money saved could make sure no one lived on the streets and could be used for education and healthcare instead.
The royal legacy will remain in this country without her through the various towers, castles, palaces and stately homes.
I also don't understand the 'there are many other things that we waste more money on' argument, that doesn't mean it's OK to waste even more on the Queen (and her extended family).