bro4bro saidRealjock used to provide that information. Someone decided not to do that anymore. No idea why.
Yes, it would be helpful.
My guess is the information was deleted from the profile pages, because the admin didn't want it obvious that so many guys have not been online in months (or years).
This is correct. Also, I think a few guys complained that they didn't want to be stalked, and wanted the last active feature removed. I don't think those guys know what stalking means.
Also, this site should have a self destruct feature. I mean, I know a few guys from this site have died in the past few years. Their account should auto-delete after x days of not logging in. It's just sad when you see a dead guy being voted MOTD.