Forum opinions, normally won't influence boardroom level decisions. The media influences them to an extent although not as much as you seem to think imo, otherwise wouldn't Man Utd have sacked LVH ages ago?
Forums might reflect more extreme opinions from either side of the coin, but the truth is at the end of the day, the board probably have many of the concerns that many fans do, just they're probably more considered and reasoned than most supporters will be.
I think you're far too confident in your belief that his job is safe, although many people who want him out are jumping the gun in believing he's on the verge of getting sacked imminently. I think if they're concerned about him they'll get rid of him soon after the season has ended. My guess is they probably have mixed views on him at present.