I have a blank Catalog front page, but Admin works in the background ? I made NO changes to any files prior to installing IH2, but when the supplied files were OLDER than what existed, I tucked the newer ones away and used your's directly, since they did not normally fall into the subset of ../custom folder.
A white page always means that some php-error occures - you must look in source code, whether there is any output, but when you messed up some php-code, it will stop for any reason. So you have to check for error messages which will be thrown from php-parser. Often this is prevented from server side to protect the customers view of website. So you have to turn on php-error-messaging. Or install same version on an local webserver, where you can savely turn on error-messages and retrieve the errors.

Another suggestion: return to original files and carefully follow every step you made...