Yes difficulty is rising, but so is the price of BTC. Since it's inception, BTC has basically doubled in value each year. Think about what that would mean for next year. Not bad ROI. In addition to mining, I'm using a bot to trade BTC and it's doing very well. Diversification is the key to success in any investment.
Irrelevant. If you need BTC price to rise above the price it was at when you made your purchase to break even or make a profit you made the wrong choice.
Not if you are investing in BTC for the long run. ASIC sellers are not selling ROI, they are selling products that mine Bitcoins. I'm in Bitcoin for the long run, and I expect that my miners will more than make ROI in the long run. If someone got into this to make a quick buck (which is clear that many people did), they are in the wrong state of mind for an investor.
Especially if you are investing in the long run. There is no scenario in that case for which you are better off buying mining equipment. Its a bust if you require the pirce to go up to make your money back or see a gain.