I heard somewhere that redirecting your /index.php to your homepage helps with SEO so I set up a 301 redirect, just wondering how true this is or if there are any downsides? I know it can create a loop somehow but thats not a problem here.
If you don't do this, you could run into duplicate content issues. Basically the search engines could get confused about which exact url to use for your homepage. By redirecting index.php to just http://www.domain.com/ you are also ensuring that all of your links count towards your homepage's link popularity. In addition to redirecting index.php, also considering redirecting http://domain.com, http://www.domain.com, http://domain.com/ and http://domain.com/index.php all to http://www.domain.com/ In addition to this it is also a good idea to manually set your preferred domain in Google Webmaster Tools.