Fedora – Disable repository updating in fedora

You can set Yum to phrase alternative repo's by downloading & installing the .rpm file of the repo. Proper instructions can be found in EPEL repo installation

Yes, you could do that via using the downloadonly yum plugins. This is described in more detail in the RedHat article: How to use yum to download a package without installing it

You would e.g. run
yum install packagex --downloadonly --downloaddir=/tmp/packagex_repo
which would download packagex and all dependencies required for the current system to only be downloaded to /tmp/packagex_repo.

There's also yumdownloader which is contained in package yum-utils which provides the same means, although due to a bug it will download both i586 and x86_64 versions of a package, and the option --archlist does not always work the way you'd want it to.

For more information see the following:

• Download all dependencies with yumdownloader, even if already installed?
• Download ALL rpms for a product
• How to download a file from repo, and install it later w/o internet connection?
• yumdownloader vs repotrack
• How To Download a RPM Package Using yum Command Without Installing On Linux

For the creation of a repo from that search around here for createrepo as there are a lot of results there. To pack that into a tarball involves only a few commands, first download the packages, then run createrepo in the repo directory and finally create a tarball from that folder plus the yum configuration for the repo. But you can also just put everything into a tarball and tell people to extract the tarball and run yum install ./*rpm in the extracted repo folder. Using the repo approach would provide the benefit that yum history and yum package listing would show from which repo a given package was originally installed.