The idea is to use Electrum on a thumb drive with offline addresses.  You could use a random computer, run electrum, import the key, pay someone, then log off and wipe the electrum.dat file.  The point is to not need to record seeds between uses--nothing is stored on the host computer, only my thumb drive.  I don't want to leave forgotten .dat files everywhere I go.  I guess you could put the .dat file in the same directory as the electrum executable, but the program now leaves them in C:\Users\Mike\AppData\Local\Electrum, which is too easy to forget to clean.

This is a brainwallet idea, in which you only need to remember your TrueCrypt password to decrypt a thumbdrive partition.  Sure I know Electrum uses a brainwallet idea too, but I want to remember "my" brainwallet password, not one defined by the program.

To me, single-use Electrum with encrypted private key file is the simplest way to pay someone with Bitcoin.  It's pretty easy to encrypt a thumb drive using TrueCrypt to store the keys as a plaintext file.  I would prefer this over even an electrum.dat file.

I don't think I trust a cell phone with private keys.  If I lose the phone, I lose control over the keys.  Also, I use an old Palm Pixi that can't run an Android app.  Also, can't hackers somehow get into my phone and try to steal my keys?  A phone as a mobile payment platform is a hotwallet.  If newspapers in London can hack cellphones, can't Bitcoin hackers?

So I still beg you (and I appreciate you responding to my post) to consider updating Electrum to avoid this change-wallet problem.  If a user imports a private key, BTC-change should go to addresses under that private key.

Regards,
Mike