You may add an type 16 ElGamal key to your public key which is easy as your key signatures are still valid. PGP 5.x does not accept V4 signatures for data material but OpenPGP requires generation of V4 signatures for all kind of data. Because you can only select from the public key ring, there is no direct way to do this. However it is not very complicated to do it anyway. Both user ids will be removed from the secret ring.
Good security has it's price.
What I do is to hit several times on the shift, control, alternate, and capslock keys, because these keys do not produce output to the screen. And it really takes long when I work on a remote system. I have the same problem. The difference is that the trust is computed at the time it is needed. This is one of the reasons for the trustdb which holds a list of valid key signatures.