Yes, talk to YOUR accountant
Yes, take Luckiest advice and speak to your accountant regarding any tax planning.
However on the subject of using your credit card to fund your $5k start up costs. I may be able to provide some insight
If your entity is already established you can try applying for a business credit card and PG'ing it. Some business credit card products today do not report to your personal credit (unless you start missing payments of course). You may be able to fund your business without tarnishing your personal scores!
I am aware that I can write off $5,000 of startup costs.
Can I still do this for my LLC if I use my personal credit card to purchase all of the startup needs?