The only team stupid enough to give up a 2nd round pick for an above average (but not an elite) kicker has already given a ridiculously bloated contract to their own guy.
If someone was willing to give us a late 2nd for him, I would gladly take it.
There are a couple of guys in this year's draft who are worth a late round pick. Plus there are free agents - Rackers, Reed, Graham to name a few - who are only slightly worse then Ghost. Most of these guys can be had for the same money as a 1st round tender, and we would get a 2nd round pick out of it.
Let's let "unclutch" Gostkowski go to bring in Shayne Graham. Brilliant plan, guess you missed the playoffs. As a point of reference, look at some FG%:
Gostkowski: Career - 85.1%, best season - 2008 90.0%, worst 2006 (rookie year) 76.9%.
Graham: Career - 85.2%, best season - 2007 91.2%, worst - 2002 72.2%
Reed: Career - 83.3%, best - 2007 92.0%, worst - 2003 71.9%
Rackers: Career - 78.2%, best - 2005 95.2%, worst - 2001 57.1% (He has 6 seasons under 80%, so I have no idea why you list him as a "little worse"....he is much much worse despite having 2 great years in 2005 and 2009)
I really don't see the need to tinker with a position where the Pats are amongst the best. Gostkowski is reliable, consistent and improving. Bringing in a guy coming off of an epic playoff choke (Graham), a guy with more awful years than good ones and that's in an optimal kicking climate (Rackers) or a guy who is known more for his drunken antics in the club scene than his clutch kicks (Reed) or a late round pick (because those usually work out so well right? It's that easy to find a good kicker, just ask Washington, or Dallas) is insane.
Yes, the Pats would get another 2nd round pick in your scenario. IMO, that pick doesn't make up for the downgrading of a critical (but often trivialized) position.