#16- Can Semi-Permanent solution cause damage to hair?

No.
No.
and more NO. 

I can't even tell you the number of times clients have called and claimed their last stylist broke a bunch of their hair during a "keratin treatment", only to find it was actually a permanent straightening system, NOT A SP-S. 

Even still, there have been times when a new client did have fried looking highlights or something to that effect, and their last stylist used an actual SP-S system. In this case, the only way damage could occur during a semi-permanent straightening is with the flat iron or rough handling of the hair. BTW, both of these factors can lead to damage of anyone's hair, at any time... not just during a SP-S treatment. Ideally, the SP-S is set at 450 degrees maximum. Hair that is damaged(overly highlighted, overly flatiron, etc) might not be able to handle 450, so the temperature should to be adjusted accordingly.  If this is the case, and the iron has to be turned down, it will also shorten the longevity and smoothing capabilities of the treatment. Some stylists don't realize that they need to dial down the iron, hence....fried hair.