If you state the office you will be attending you will get more accurate info as they often have different requirements. Most are pretty easy as it is as much a chore for them as it is for us and they just want to get them out of the way
Different offices have different requirement. Not all need a photo. Waiting time at Jomtien is 20 to 30 mins. The form you mention is TM47 for 90 Day report
I have had the request at both BOI in Bangkok and Jomtien Immigration. It's nothing, just making sure you are not hiding anything loke deportation stamps etc
It usually signifies a passport where visas have to be applied ahead of a visit. Often these visas are hard to get. As an example Singapore is a very strong passport as they have visa free entry very extensively. Indian passport is weak as they mostly need visas and are hard to obtain for say USA, Schengen etc