Do I need my passport, as a foreigner , when flying domestic on Bangkok Air. ?

I need to surrender my passport for 6 weeks for renewal..

Other issues I may encounter ?

Have you been asked for proof of onward travel when boarding your flight ? (If so what airline)

Hi! I’m flying from Chiang Mai to Koh Samui this weekend via Bangkok Airways. We’ve read that the carry on luggage limit is only 5 kg which seems impossible since my carry on luggage itself weighs 3.15 kg. Has anyone had any experience recently where they haven’t weighed your carry on? Seems very unrealistic!! (They do allow 1 checked bag weighing 20 kgs)

Attempt number 3 failed to enter Thailand. How on earth can they delay the layover flight by a week. What a joke.