The importance of the Max Starks signing
Max Starks has been consistently one of the better Steelers offensive lineman over the past several years. Yes, Starks is rehabbing a torn ACL injury but he is expected to be healthy shortly even though he was listed on the PUP. Consider this. Starks has 8 years of experience and is still only 30 years old. 30 isn't "over the hill" for a left tackle. Starks knows Ben Roethlisberger's playing style very well and that can't be overstated. It's well documented that Ben likes to extend plays and having a LT that is proven and whom is trusted with protecting Big Be's blind can't be underestimated.
What if Mike Adams isn't ready to play week 1? Starks is literally a huge security blanket for this team. If you need proof of that, refer to last year. Starks was able to relieve Jonathan Scott from his duties after a few poor weeks of play. Starks will do the same this year if Mike Adams isn't ready.
Let's also consider leadership. Ben is clearly the leader on offense but Max will be a close second. With the loss of key longtime leaders (Farrior, Ward and Smith), it's important to sustain good leadership. Having Max Starks back certainly helps out the offensive leadership.