Yes, ending fossil fuel subsidies would be good for the environment, because subsidies allow inefficient practices to continue. Without the subsidies, businesses would be more likely to invest in green or other alternative energy, that would be better for the environment in the long run. Any time an activity is subsidized, there will be more of it. Subsidies for fossil fuels should end to encourage businesses to develop alternative energies.
Wanting and something doesn't make it happen immediately or make it possible. Technology is ready when it is ready and green tech simply isn't yet. Eco friendly technologies are not as efficient as fossil fuels as of yet and most require fossil fuels to be created or to function. Fossil fuels will be Phased out when there is a viable replacement. Phasing them out prematurely creates economic losses which in turn reduces funding for research.
I believe that ending fossil fuel subsides is bad for both the environment and the economy. If production costs increase, then the impact on the environment will be greater due to oil companies using more equipment and possibly unethical ways of producing the oil. Subsidies help keep companies from having to resort to ways that my possibly harm the environment in by lightening their financial burden.