You have set up some consequences (taking away his skateboard and TV privileges), but they aren't really related to his misbehavior. I am going to give you a few ideas that you and your husband could use or adapt to your situation. Once you and he have decided on what you want to do, meet as a family and explain to your son (and the rest of the family) what the rules and consequences are and then follow through -- both of you.
Chores: Decide what they are, who is doing what, and that they will be completed before study time. If not completed, then your son has to complete them after homework time -- perhaps during his TV or playtime.
Homework: Set a time that homework is to be done. For example, from 8:00-10:00. If the work is not complete, your son may not stay up. He can get up early the next day or take a lower grade on it.
Allowance: Set up conditions -- if chores and homework are completed every day without your having to nag at him, give him the allowance. If he has not followed through, do not give him money for candy or church offerings. Calmly but firmly say, "You chose not to do your homework (or chores). Maybe next week."
Clothes: This might be a losing battle and battles with teens need to be chosen carefully. Decide if this is worth fighting over.