Is this the same place as your previous thread (garage) or is this a seperate building, if its the same can you please keep to one thread discussing the same subject and not open multiple threads.
Secondly - We as a forum have a diy section and members status so members can help out with those simple diy tasks that just require a little advice from a more experienced source, we also need to ensure the safety of the DIYer and that of his property and family in the advice we give, when you start to ask for a step by step guide to wiring out a shed and/or garage then it goes beyond what our DIY section is about, considering the lengthy list of questions, the work you are undertaking then I would strongly recommend you bring a competent Electrician onboard.
Wiring supplies out to sheds and garages is really not a DIY task and should be done at a minimum, under the supervision of a competent person and I don't mean through a forum, the supply type and earthing arrangement of the property can mean you have to carry out extra work to ensure compliance.
During and after work is complete it should be subject to testing to ensure its both safe and compliant, without a multi-tester or several individual testers then this wont be possible, even if you can aquire such testing equipment it comes down to knowing how to interpret the readings.
It is on this note that I advise you to bring your own competent electrician on board if only to guide you in the work your doing and to commision the installation after, looking through the pictures and reading your posts, there are a lot of areas I would consider need checking that you have done them correctly and they test through, family and property safety is not worth risking on saving a few quid.
Please take this as constructive advice, the level of questioning you ask is very basic even for a DIY so it does concern me about other parts of the install that usually are not recommended as a DIY project.