ghee in moderate quantity is good for health when it's pure ghee.
it won't make you fat. if you are already overweight you should consider to increase your physical activity to burn more calories than you take.
but excercise alone will be of no help unless you decrease your calorie intake.
regarding the taste of olive oil, it differs from person to person.
for example I like it, but my friend doesnt like it. so you will have to try it to find out if you like it or not.
but olive oil has a lot of health benefits I suggest you make olive oil a part of your diet.