uK is not s Schengen country. Within the schengencountries you are free to travel and I believe to Switzerland too. but UK visa is for UK and the UK part of Ireland only
I lived five years near Chiang mai and loved it fogproblem about two months , beginning of the year. Bearable but better to go somewhere else during this months
There is an official website that mentions all hotels suitable for test and go or sandbox. You choose a hotel and are immediately connected to the booking site of the hotel. If you use that you do not have to search if hotel is usable