Reading this post gave me the shivers, as it dredged up a bad experience from my past. 2007-2008 I was playing the credit card arbitrage game - get a 0% cash advance, put the money in a high interest savings account, bank the interest. Simple, worked well.
However, on average, can't I get a better return from the stock market? I ended up using credit card balance transfers to help fund my margin loan for stocks. I got badly burnt (thankfully I had the income to keep above water). However, I did loose tens of thousands of dollars in real money, and further tens of thousands in opportunity cost, as I didn't have the cash flow to buy stocks at the bottom of the GFC that I otherwise would have. I got through, and still invest pretty aggressively.
However, your thoughts in your initial post seem like the same state of mind I had at that stage. I'd be a little cautious about doing this again with money that is for an expense in the short term.