you made a valid point.

let's just imagine that residents (expatriates) were made to pay taxes, I'm sure that would qualify them to have a voice in the upcoming Parliament

Again , i don't see that happening in the gulf. because of many security , social & tribal aspects.

In the first place, What Qatar want to achieve in the long run is to become a constitutional monarchy not an electoral democracy or a republic

Certain review of citizenship is a must in the long run i guess for that to succeed. specially since locals are outnumbered by expatriates in a huge scale