Well, it's been a while since you asked, but since I just did it to test it, I think I can answer some questions:

I did it from scratch though, but my issues are likely to be similar to yours (you just may not know it yet). This will assume most people who are trying this know the basics of git. This also assumes you have the rhc tools installed for your os.

So, let's start from scratch. I made my gear and set it up. Then I did a git clone into a working directory from openshift (this is required to sync up repos and how they do hooks). I then extracted the c5 folders into that directory, and did a git commit and push.

This started the livedeploy on the server. I went there, and saw the install screen. SWEET. Wait, no, it said it couldn't write to the usual directories. Ruh roh. Oh, wait, git doesn't pay attention to directories permissions except for executable. So I try over again, this time making sure that the directories have the correct permissions. But that wasn't the REAL issue. Nope, the real issue is... git didn't create the empty directories (for packages for example) on the server. Well then, that IS an issue.

So, we move to the backdoor. I loaded up filezilla, and set up a sftp to the server (details can be found here:https://subinsb.com/how-to-use-filezillasftp-to-update-site-in-opens... I then got in there, went to the app-deploy directory and then repo. That gave me the c5 files on the server. I pushed up the entire folder again, just to make sure any other empty directories got in there.

Next comes the database. I used the php with mysql and phpmyadmin cartridge, so I was able to just log into phpmyadmin, make a db, and then I created the c5 user for that db. I save it, then started the install....

But wait, there's more. See, openshift wants you to use their environment variables to connect to the db. But the way c5 works, that won't fly. So I had to ssh into my cartridge () and then I used to find the server ip. I inserted that, that, and the installation flew right along.

If you already have a project you are trying to upload, I recommend checking the permissions on folders as your first step. and then to ensure that there are no empty folders.
Now that all my folders are populated, I plan to re-download via sftp, and then if I need to upload any changes, I can commit that via git, and it will have all the correct info from the server. Alternately, I could just work via sftp and only upload when I've pushed to git for any packages I may be working on.

I hope that helps someone looking to use openshift!