I've posted on the "3rd down pass pro specialist" Pat Kirwan theory in other threads. It hasn't been experimented with, much less caught on as a thing yet, but that doesn't mean it couldn't be a viable option with the right player. It doesn't have to be when playing from behind necessarily. It's definitely an idea to be used in obvious passing situations.
I could care less if he's older than Methuselah (969). If he can still play better than our current options at RT we just need a one year rental. $1.2 Million for a starting NFL tackle is a steal.
In regard to injuries, the Achiles was 12 years ago, and the Knee was 7 years ago.