With the rolling cap there is no need to front load deals anymore because the unspent money just rolls ahead regardless. For example, if a guy gets paid $5 million instead of $10 million in year one, but the reverse is true in year two, the $5 million savings from year one will roll over to the next cap to pay for the expensive 2nd year. In the end, it all works out the same, so it incentivizes teams to use back-loaded deals even more as the savings in the early years can be rolled ahead to handle the expensive years should they be in a situation where a player is too valuable to cut for cap reasons. In other words, it gives teams more flexibility, and if they are cut-throat, it saves them money too.
Similarly, the advantage of signing a guy to an extension a year early to lower the hit in future years is similarly of little meaning- that is unless your team is flirting with the 90% cap number that would mean a loss of rollover cash.
The real advantage of signing a year early is because of inflation. NFL inflation far outpaces the national average by a ton- player pricing goes up by something like 10% a year on average (The NFL salary cap today is nearly four times larger than the original one set twenty years ago). You sign Earl and Sherman now, and you might save 10% compared to getting them next year. And if they hit UFA, their prices would rise even more. Thankfully, there are always tools at JS's disposal for making those contracts fit into the 2014 budget, even if money is tight. I fully expect both to be extended. Short term money concerns aren't really an excuse.
Regarding Bennett, only twice have PC/JS been outbid for a player they wanted back: Hasselbeck and Carlson. Both were grossly overpaid and were at the time mediocre NFL players. Seattle stretched beyond their comfort zone to retain Red. They will do the same here for Bennett. Maybe Bennett does leave but I expect Seattle to be very competitive, and I personally think trying to replace his production, versatility and chemistry with a low cost alternative is a foolish gamble (I think Pete sees it that way too).
Budgeting him is tough, but I personally do not view Bennett and the LOB as a zero sum game. If that means letting some lesser players go at other positions the next couple years (Tate, Baldwin, Wright, etc) so be it. If it really was a choice between LOB and Bennett I'd choose LOB, but I don't think that should diminish how big of a negative impact losing Bennett will have.