Hi Rowan,
The rewrites you put in the .htaccess file won't work correctly if you aren't using the domain name to access the site. The rewrites won't work using the temporary address.
The best way to test the site before you point the domain to it is through putting the domain into your hosts file. You can see more on how to do this here:
https://support.blacknight.ie/index....barticleid=169