So with everything you've said, do you think changing back to TV-14 with a three hour Raw would damage revenue, or increase it?
It would take a lot more than just making it TV-14. It's a lot more complex than that.
If they were to change to TV-14 they would have to change their entire business model in almost every department. They would likely increase revenue on live show attendance and PPV buys as they would be then targeting a more broader demographic, they would likely take a short term hit in merchandise sales as John Cena is by far their largest draw for merchandising. There are arguments to say they'd lose a lot of revenue in advertising as a lot of advertisers wouldn't touch them.
People sometimes forget that Raw only went to TV-14 in late 1999. During the boom in late 97, al of 1998 and most of 1999 it was still PG. But good PG as JR refers to it. Smackdown changed to PG after it's first 4 months of broadcast and remained that way until today.
In summary it's not about the PG or TV-14. I believe they have to make the product a lot more relevant than it is, it simply isn't relevant at the moment. They have to drastically improve their creative processes and output. It doesn't connect with today's culture. It isn't must see TV any longer. The problem however is they are intelligent enough to still make a lot of money out of the product as it is, this and also factoring in they are a cash rich company with over $160 million in cash at the bank as per their last annual report.
To change they must be faced with 2 things, the prospect of financial ruin (like 1997), and some decent competition for Vince to fight (again like 1997). Neither of these are likely to happen soon.
Therefore, what's the motivation for a change? There isn't one.