You should. It was fairly easy, and the results are way worth it. The mask is elastic plastic and hard to break. The jaw is a bit more sensitive, but if you heat them up well with a blowdryer and don't bend anything 90 degrees, you're good. In the end, it's dramatically better than the stock horseface mask.
Regarding the dreads, if I pull harder, the rubber doesn't gape. So I think as you say, it's the paint cracking due to glue covering it. Pretty shoddy glue work, if I may say so. How does yours look? Any close-up dread pics would be greatly appreciated.
I'll give the blowdrying a try soon. My dreads don't show any cracks like that, I'll take some pictures soon so you can see how they look. I'm not sure whether the glue may have done that though, I think it could simply be from strain that was applied over time.