(5) is too high: it´s one riff only with the one bend the E String. You could argue (3.5) fur the non beginner tuning and for it´s rather fast. But (5) means you master that and you advance to Advanced Class, and you got one whole week. In comparison to our library it feels an ok challenge for beginners if they make the 99 over the week they make it to Int class - that´s somehow the (3) definition.
Darkness sy - hard to rate a bit... yes (6.5 - 7) is a valid rating also. From my POV the rhythm is damn fast and very hard to make sound right, i take that into account esp. in Rhy path - so i´d go (7.5)
Rod