Ramadhaan & Fasting

Questions related to Qadha and Kaffaara for fasting

Q: Are the rules same for intentionally breaking a fast in Ramdhan, and not keeping a fast at all for no valid reason? Under what circumstances do we have to do kaffara and under what circumstances do we have to do just qadha? Does breaking a fast just because you were hungry or you felt you don't want to fast anymore need qadha and kaffara or just qadha? Does not fasting at all need kaffara as well as qadha or just qadha?

Kissing one's wife while fasting

Q: Regarding kissing the wife during Ramadhan fast. I knew that it was permissibile to kiss the wife as long as it does not lead to anything further. Only recently did I become aware that only kissing without the tongue was meant as kissing with the tongue would require qadha and kafaarah due to the exchange of saliva. As kissing with the tongue is the norm I had not made that distinction till now. Am I required to perfrom qadha and kafaarah or just qadha due to misunderstanding as I see in nurul idha that kafaarah will not be required if someone misunderstood the hadith?