So one of the last tasks in getting my inherited SBS up and running was to fix the autodiscover and RPC over HTTP. With the help of the Exchange Connectivity Test I've troubleshooted my way through getting fixed; DNS has been setup correctly with SRV records, ECT confirms this. SSL Certificate has been installed to the server (definitely not as straight forward as the console leads you to believe).
Last step was getting the RPC over HTTP repaired, on inspection there were no entries for Rpc or RpcWithCert under "SBS Web Applications" so I followed the process here to attempt to repair. This appears to be have been successful, the entries are in place and such, but something hasn't gone right. I have multiple extra sites in IIS been created that give an error when attempting to check properties, are stopped and don't expand out. Worse though the Autodiscover is broken but the rest of Web Applications seem fine, I.E. OWA loads fine!
Browsing to https://remote.domain.xxx/Autodiscover/Autodiscover.xml gives "HTTP Error 503. The service is unavailable.". But I can confirm the autodiscover.xml file is there via browsing from IIS though.
This was definitely working fine previously, the last step on the ECT was just the RPC - this is checking via Autodiscover!
This is a screenshot of IIS now. (You'll notice also RWW is missing, another to be "repaired" but I can't find any documentation what so ever to do so).