For the first point it will only work if the application is in your $PATH.. /usr/bin, /bin, /opt/bin/, etc..

You should be able to run the command like "./aptly" if its in the same directory you're in.

I know theres a way to get a the repo info.. still looking. Things like "apt-cache show package_name" give a ton of information including version, and section (the control file), but doesn't list repo. Interesting.