The frequency is 50Htz in both nations, so there is no problem using any devices that have any form of clock or timer. The voltage is also 220v in both countries.
They are both totally compatible regarding electrical supply and there will be absolutely no issue.
As for connection, adaptors, they are freely available in almost every supermarket and market all across Thailand and cost on average a about 30THB (about 1USD).
You may not even need to buy one though, attached is information about Chinese electrical sockets
as advised, just contact VFS. No need for an agent or the embassy.
VFS are actually quite efficient and helpful.
If you go to the British government's website in this link and start the process by reporting it stolen, they will also give you the contact details for VFS after you provide the answers to their questionnaire
The the British emergency passport is an off-white colour, not the standard burgundy colour. It is also only valid for emergency travel (which must be declared/submitted with the application for the emergency passport).