@ Andante - with a short credit history - the US Bank card - you may get approved but it may be a low limit. (may be a decent one too, never know). I would definitely give it a few months before apping for another card. As far as understanding AAoA. I'll explain it below.
Lets say you have one card currently. You've had it for a year (12 months). With only 1 card, you're AAoA is 12 months. Let's add another card in now, it's 0 months since you just opened it. 2 cards now - you take how long both cards have been opened (in this case - 12 + 0) and divide by the number of cards (2 in this case), you're AAoA drops down to 6 months. If you add another card (another 0 months), it'll drop down to 4 months. Generally, the longer the AAoA is, the more reliable you seem to a lender. Generally, lenders like AAoA's of 5 years plus.
As far as other expenses go - insurance, utilities and mortgage - I would review to see if they charge for paying with a credit card. (IME - they usually have a surcharge, I looked at all 3 of mines). It may or may not be worth putting those on a CC because of that. I would definitely do the math and research before changing those. I'll throw a few examples of how I have my expenses listed.
US Bank 5% - 5% categories selected are cell phone providers and dept. stores - I put my phone bill and any dept store purchases on this card.
Chase Freedom 5% - current categories are gas, tolls and drug stores - all gas and toll purchases are on this card for this quarter.
BoA Cash Rewards - my backup gas card.
BoA Travel Rewards/Cap1 Venture - all travel purchases.
Best way to monitor and know what card is best is through Excel. It's a useful tool to help itemize and figure out what works best and where bills are going to.
Also - just an FYI - I would make sure your income is updated in Chase. They are known to give auto-CLIs but usually require updated income information. I would check that.
Edit - there's 5 thresholds that hit your credit dynamically (meaning, every time you hit them you'll experience a drop in your score, but once paid, it goes right back to where it was).
8.9%, 28.9%, 48.9%, 68.9%, and 88.9%.
The average hit you take when hitting any of them is between 10-20 points. In your case, 36% would be a hit of 2 thresholds, which could be anywhere between a 20-40 point loss. When you pay it off, it'll come right back. I wouldn't worry about it too much. Just manually make extra payments a month. I usually pay off my cards atleast 2-3 times a month. Some cards I let the statement cut and then pay, others, I just make a full payment whenever something posts. I do let atleast 1-2 cards report a small balance of ~ $100.
OP with Chase you can set up autopay to take care of the entire previous statement balance, pay that on the due date. With a $8,500 limit and typicall spend of $500 I would not worry about the finer points of FICO points. You may lose a few points, but not much, and your month will be simpler with autopay.
