I noticed the best companies pay everyone according to the amount of classes they teach, so everyone is paid equally according to the amount of work they do.
This is a bit simple. What about the quality of the teaching? You yourself mentioned the 'backpackers' who don't really care about classes. What if one teacher is good and one isn't? Do you pay them the same? What about more experienced teachers and less experienced ones? Do you pay them the same? What if one puts in a lot of extra preparation? What if one has to do a lot of morning classes? What about class sizes? Levels? Ages? There are lots of factors that this doesn't cover, you can't just say pay everyone by hours worked regardless, it doesn't work in practice! The teachers complain! (Trust me on this one!!!)

Also, the best companies will give the teachers the freedom of choice, to get a company apartment or to get a housing allowance of 2000rmb per month, and also airfare paid in monthly installments such as 500rmb per month for airfare added onto the monthly salary
2000 in large cities maybe!!! In smaller cities this will likely be a *lot* less!!

Airfare per month is an interesting concept, may suggest that to my boss, though not sure if the teachers would like it like that, or all in one lump sum. Could offer a choice perhaps.

Lastly, working conditions are a *major* factor in the school, I would be interested to hear more about this mass walkout Fidel!