Would this course be suitable for a novice when it comes to electricals on cars?
Absolutely! Paul (aka ScannerDanner) Danner structured course, specifically, for beginners.
Secondly the cars you have stateside are more big engined petrols we have much smaller engined petrols and lots of diesels vehicles are the skills on this course transferable easily enough to smaller vehicles and diesel's?
Yes. The techniques that ScannerDanner teaches are universal. They will transfer to areas reaching far beyond the automotive industry. These skills and techniques can be use to diagnose your household appliances. I have used them to fix my own, as well as a few friends' furnace problems. Just last week, I use the skills that I learned from ScanneDanner to diagnose and repair my automated cat litterbox. A hall effect sensor, is a hall effect sensor. It doesn't matter if it is telling the position of a crankshaft, or the position of a cat litterbox.
Third question is about tools many of the tools listed specifically on Scanners Danners Amazon aren't really available in the UK is there similar ones available here that I can use similarly to what you guys use over there?
A bi-directional scantool, a volt meter, and an incandescent test-light will take you a long way. You don't have to get fancy with a scope for most things.
I however usually shy away from electrical issues and send them to local garages. I obviously would like to change that.
This video
is a great place to start.