I'm not quite sure I understand where the "polynomial time" came from, although there's a strong whiff of Gödel in that statement.  While I recognize that we cannot prove absolute correctness we can at least do some structural sanity checks, assuming there is an indeterminate number of items of arbitrary type on top of the stack or something.  Heck, Java does a heck of a lot heavier check than this when loading code.  And I don't see how this would change Bitcoin at all, or eliminate any possible "strange scripts" people could come up with.

I don't really understand the "minor is not the gatekeeper of transactions" thingy either.  What prevents double-spend transactions from entering the blockchain?  I'm assuming that anyone can broadcast anything they want almost by definition (i.e. we have to accept that badly-performing clients exist).  Either the miner has to block malicious transactions or we have to ignore malicious transactions that are already in the block chain.  I recognize that misformed scripts are nowhere near "malicious", but the same rules could apply here.  We don't need 100% buy-in by miners either, this doesn't really change Bitcoin, miners already are permitted to accept all or none of the transactions at their discretion.

I realize that I'm entering a very intense firestorm with this opinion and would probably immediately be declared too inexperienced and/or wrong