I'm planning to stop at Frankfurt for about 8-9 hours, I have a valid Schengen visa with multiple entries. I have following questions,

1. Do the immigration likely to grant me an entry to Frankfurt?
2. How far by train from the airport to the city?
3. How safe it is for my checked baggage (checked through from LHR to BKK) to lay at FRA for long time?

Please answer in Thai, my keyboard is not Thai so typing in English.