I had the same idea. I wanted to have the Powerlitre for the closing mechanism, in part because PP and PL open so smoothly that it's impossible to have them hanging from the keyring, and in part because for some accessories which might be fit in the hole where the bits go, it would be better to have the closing mechanism so not to have to keep it squeezed all the time.
But I noticed that it's not possible to remove the corkscrew, so I decided to go for the Powerpint. I simply tightened the screws for the pliers so it doesn't open anymore so easily (I have it hanging from my keyring), and I'll just squeeze when it will be needed. After all it's not my main MT (that's the LM Surge). I have this just in case because the LM Squirt is just a toy and I hate non-lockable stuff.
I'm afraid you can only remove the corkscrew with a drill bit in the rivet, or with a metal saw. But I do not see how you could fit something else instead.