yes ! and dont forget looking before with your bank if you have insurance with your credit card about covid. for me is ok i have covid policy inclued on my insurrance with visa premier i dont need to pay one more :)
if you have your paper with pdf format just do a screenshot for have jpeg format. cettifcte insurance need for apply thai pass also your booking test and go 1 night package your passeport and vaccine certifcate with qr code if possible for automatic and fast check
they dont ask the flight ticket only the number and date of flight. if you change company you need to do again your thaipass. put the return date dont need to be the true dont worry.. i have 6 month flight ticket i apply for 3 month ( the longer of my visa non immigrant o thai wife)