I don't think you should try and get your parents to bend their standards so that you can party more with your friends or buy clothes with their money that they wouldn't approve of.
If you want the freedom, then take the responsibility: get a job, help out more around the house, start taking on adult responsiblity.
yes you should focus on schooling, but on the weekends or during all that free time you are now using to spend time with your friends you could be babysitting or having a part time job.
True it won't be enough to pay for you to live on your own, but you could start saving and thinking about all the expenses you will have to pay for after you move out: food, rent, clothes, gas, car insurance, electric bill, water bill, schooling expenses, etc.
Your friends don't have curfews,
do they have jobs?
Do they have parents that pay attention and love them enough to checkup on them?
Do they pay any bills?
What do they do late at night? drugs? alcohol? parties?