Wow, many thanks for that Scott couldn't ask for anymore. Very clear explanation. I find it sometimes difficult to find an answer using many peoples opinions.
And a Panel Schedule would be grand!

Sorry to ask another question to you're answer but would I also be right in thinking that the KVA requirement would be selected on the highest KVA value of load in the schedule and not overall system load as the transformer KVA rating will allow a tolerance over that value as not to over rate the install?