I use openssl's blowfish, though my file doesn't contain usernames or passwords, it merely contains lines of "site: password hint".
The safety of your operation sounds good. Remember that bcrypt shreds the original file N times after encrypting, so there is nothing recognizable in your RAM at that spot after power off.
Possible vectors to your operation would be swap, and of course owning the machine.
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The bcrypt app has one weak point, to gain the 448-bit key it repeats your password until it's long enough. So if your password was "bear" the resulting key would be "bearbearbear..." up to 448 bits.
This is only a downside if you happen to have a cyclic password, then it can be decrypted only using the smallest portion.