Also, is there a way to prevent sources.list from being overwritten?
Create or edit /etc/apt/preferences to include
Pin: origin www.blagblagblag.org
If other repositories are already listed in preferences, make sure blag is set to the highest pin priority. The default value is 500, I think. Apt will still grab packages not in blag but won't upgrade any blag packages with non-blag packages (even newer ones). So apt and sources.list from blag won't get replaced.
Note: pinning works with apt under debian. Never tried it with fedora. Guess it should work, but ??? Might want to google it first. Good luck.