I don't know about the others, but I would bet anything Edgar will be back. Even before Sig said "he's been complaining like this for the last 5 or 6 years," I just got the impression he was bitching more than actually thinking about quitting. I find his complaining ironic because he's the one who always says he can't stand whiners. He's coming off as pretty hypocritical now, IMO. Not only that, but even if he wanted to quit his fishing job, what else would he do? Sell cars? It sounds like the only job he's ever had was being a crab fisherman so his options might be limited, especially in this economy.
As for Jake's dad, that couldn't have ended well. Darrington is out in the middle of fucking nowhere. If you find an abandoned car in Darrington, the owner of that car is going to be dead. My only question is did he off himself or was there actually foul play involved?
Oh and one last thing... I remember an episode where Jake said he makes like 3 times more than his dad. Now that I see his dad actually had a "professional" job (a counselor at a high school), that's just sad. I know Jake probably does well for himself, but there's no way a longtime counselor should be making 1/3 of what Jake makes. This is another shining example of why people avoid careers in education -- the pay is awful.