lockstep
Prince
I added culture to the opera house before, but people didn't like it because it was harder to get tourism victories.
You could remove one base culture point from the Theater (so that it becomes +1 culture, +1 culture from dyes/cotton/furs/silk) and add it to the Opera House (so that it becomes +2 culture).
I think the best way to help tall empires get tourism is put 2 GW slots and a theme bonus on each national wonder. Giving tall empires more policies won't directly help them get tourism... there's not many tourism policies.
I'm not sure if tall empires need help with regard to tourism, but adding GW slots to some of the national wonders would be a sound way to buff tourism. The National College could receive 1 writing slot, and the Grand Temple 1 or 2 art/artifact slots.