Last time I checked, normal people don't have liver disease, and your mayo clinic link agrees with me. Also, when comparing things, you must make sure that your comparisons are precise. Semantics can be very misleading. Determining a healthy level of consumption of sugar does not equate to a difference in sugars.

Health and medicine related research can be particularly difficult to understand because there is much deliberate fraud as well as great difficulty in correctly controlling some variables. A basic understanding of sampling, however, is enough to see that the research does not bore out a reason to believe that this one demonized sugar is different than other sugars for normal humans.

Whether or not sugar consumption is limited when not going for HFCS really just depends. People who don't know what they're doing (most people) will make up for it really easily. Exchanging table sugar and pancake syrup for agave and honey does nothing unless intake is decreased, and intake will not decrease without changes in satiety, which is something the vast majority of people will not do.