Default algorithm and gpgme questions

[Hans Alves]

Hey,

I noticed that when I use a symetric cipher, the default algorithm is
CAST5 which allways gives me this warning when decrypting:
gpg: WARNING: message was not integrity protected
So, is there a way to change the default algorithm to AES or TWOFISH 
without having to specify it as a command-line option every time?

I also noticed that GPGME always uses /usr/bin/gpg even though I have a
later version installed at /usr/local/bin/gpg can I get GPGME to use the
newer version, and if yes, how?

Thanks,
Hans