I would certainly like to see the spending put into the nuclear deterrent moved to areas of far greater need. A weapon so frightening it can only be used in retaliation to a first shot is of questionable deterrent value.
Now that the technology for precision attack is very mature and high value targets can be reliably eliminated by conventional arms, the main advantage still in the nuclear weapons favour is the ability to take out a great mass of targets at once. Unless we resort to WW2 style city bombing, or wish to take out the Chinese army, I don't think it's a pressing need.
I don't think the security council seat claims could ever prove credible - it would be a very public statement effectively endorsing motivation for moves towards nuclear weaponry by other states and confirming all unsaid rules of the current nuclear club: disarmament is a great idea - you first; no one should have nuclear weapons, unless you already have them, in which case you should discourage all other nations from desiring them, as such weapons are better in your more experienced hands.