Don't know who told you that it is more concentrated. The calculator at www.screwybrewer.com shows you the difference between cane sugar (sucrose) and corn sugar (glucose/dextrose), and it's minimal. At the end of the day, you should use the cheapest table sugar you can find because the outcome is exactly the same.
To learn what levels of carbonation you like, do several different amounts, label the bottom of the bottle, and don't look when you taste it.
It's likely that the your CAL "foamed over" due to too high temperatures during fermentation. A properly filled LBK with a total of 2.13 gallons in it, with CAL, should never foam over. The higher temperature got it very active - and created the cider-like flavor you taste. Another week in the LBK is good for the yeast to cleanup, but it's very likely that at 3 weeks you will still find it cider-like. A good 4, or even 6 weeks in the bottle should reduce that somewhat. The key in the future is to ferment with a wort temperature closer to 65.