Would combining these be okay to do, or foolish?

My advice to you is to transfer your existing balances on to the card with the best deal, when that deal is up review the situation - only make small purchases on other cards and pay them off immediately to avoid interest payments while still contributing to your overall credit rating, most importantly avoid any high balance on a card with a high interest rate, try not to carry a balance at all when your 0% deal runs out - if necessary use savings to pay balances off as the money you would make on savings is far less than the interest you will pay on 99.9% of credit cards. Instead of combining the cards just don't use them - be responsible with your credit you never know when you may need a good credit rating - hope this helps