The 1.5 L engine with Turbo charger will need 98 or 100 RON, not only for good power output but also for Turbo Charger's life as well as engine life. 98 and 100 RON is not available in Pakistan. Using 87 RON as fuel(Super) in a car with turbo charger, im sceptical what the result will be after a few months.
Secondly,I am not sure if Honda techs in Honda workshops and Pit shops are trained to work on turbo chargers or turbo charged engines. and then what about local mechanics.
Fuel consumption wise,2.0L might be having better economy than 1.5L after all. A turbocharger forces more air in to the engine so it can be able to burn more fuel. i doubt anyone will be driving off boost on a turbo charged engine, however in the off boost state the engine will not be consuming as much fuel as when the turbo is really spooling thus making it more efficient.