I would like to run apache as the user "ubuntu" so that we don't have issues with file permissions. We deploy files using "ubuntu", but if the web server creates or updates files, the user is changed to "www-data" and it's a pain to fix permission issues all the time. I know that SUExec does something like this by running apache as the owner of the root web folder. Are there any security concerns running apache as the user "ubuntu"?
I think I may have found the answer to my question. Since the user "ubuntu" is part of the sudoers file and it has the ability to act as root, badly coded sites could be especially vulnerable if user-entered parameters are not properly escaped or sanitized. This could be a problem with PHP's exec() function, for example. I think I will setup a new user and run Apache as that user, change the owner of the web folder and it's contents, and setup our deployment service to login with that user. Should be safer this way.