Why are you flying through Delhi so much? Would you need a transit visa? Pretty sure Turkish flies to male, would be more direct than your current route
If you want to reduce the surcharges out of London, call in for a second stopover in Europe and the departure taxes will drop. Brussels, Zurich or Istanbul
Open jaw enroute is likely to be denied
Maldives to Singapore, Taipei, YVR is a better route home unless you have specific things you want to do on a connection elsewhere