Okay, so I have not read every single post so I may have missed where it should have been mentionedf that each company can be a customer of or venbdor to the other. If Company A credit card is used to purchase something for Company B then that is a billable expense, which can include amarkup when invoiced. This does require that each company is a unique entuty with a unique FEIN. If both companies are sole proprietorships of same sole owner (or even simple LLC) then truly owner draw and owner contirbution make the most sense.
In the world of small business it is not always convenient or even possible to secure credit cards in the name of the business; most sole props use personal cards instead. And due to fund shortfalls it is not always possible for one company to reimburse another, in which case intercompany loans are the way I see to go. In the corporate world you can have loans to and from the shareholders so why not between 2 companies that exist at arm's length.
Regarding Finfrock, and current due on long term liabilities, I have been there and had to do that for banks and other lenders, the sole reason to determine cash flow and liquidity based on everything possibly due in 30 days. It means nothing for tax purposes, only for borrowing.
