You can get an idea of what will happen if you just assume all of your table sugar gets fermented. If you hadn't added table sugar, you would have expected your FG to be about (1-0.74)*60 = 15.6 points (assuming 74% attenuation). Since you expect the extra 13 points to be completely converted into alcohol, you would expect to see a reduction of a point or two in FG due to the effect of extra alcohol on density. So, I would expect you should've seen 14-15 points in the end, which you did.
You are right...this process is limited by the alcohol tolerance of the yeast. Just because you have %74 percent attenuation listed on the package doesn't mean your 1.200 wort will go down to 1.052 if your yeast poop out at 10% alcohol. You would rather expect it to finish around 1.124.