I have several newer credit lines that I opened to get cheap financing for buying some appliances. They are paid off now, but they are really hurting my average age of credit line portion of my credit score. If I got credit line increases on my oldest credit cards, and closed the newest credit cards that would improve my credit score, right?
I wrote How Old is Your Credit Card? some time ago. The answer is yes, this helps the credit score, but this factor, age of accounts, is pretty minimal. Grabbing deals, as you did, I'm actually down to a "C" for this part of my score, but still maintain a 770 score.
Credit Score is rather misleading, each provider of credit uses their own system to decide if they wish to lend to you. They will also not tell you how the combine all the factoring together.
Closing unused account is good, as it reduced the risk of identity theft and you have less paperwork to deal with.
It looks good if a company that knows you will agrees to give you more credit, as clearly they think you are a good risk.
Having more total credit allowed on account is bad, as you may use it and not be able to pay all your bills.
Using all your credit is bad, as it looks like you are not in control.
Using a “pay day lender” is VERY bad, as only people that are out of control do so.
Credit cards should be used for short term credit paying them off in full most months, but it is OK to take advantage of some interest free credit.