Sometimes my aliases get in the way of binaries in $PATH. The aliases here seem to me to run the same danger.<p>There was a post about prefixing aliases with a comma some time ago. I thought that might be of relevance here (can't find the post anymore...).
The idea being that you use aliases like this:
alias ,somecommand="echo foo"<p>This avoids collisions and also allows you to iterate your aliases with autocomplete by typing , and then tab. Very handy :)
GNU tar can automatically decompress with -a, which might save some typing with these. Relatedly, you cannot append to a compressed tarball, which means those aliases will are improper if you try to append. Replace z with a for aliases that can append with GNU tar.