Qadha and Kaffara

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?

Previous years qadha fasts and kaffara for breaking a fast intentionally

Q: As Ramadhaan is nearing so I thought of covering up all my Qadha roza but I don't have the exact count of the Qadha roza. What should I do in this case? Also I have Qadha roza of the previous few years and I don't remember how many they are. 

I had once broken my fast when I was young but baaligh, but I did not know that it was a major sin. How do I cover up for that?

Niyah for Nafl Fast along with Qadha

Q: I have learnt that one cannot make the niyah of a nafl along with a qaza sawm but for the sawm whose days are specified (e.g. Monday, Thursday, Yawm-e-arafah, Muharram, 15 Shabaan but not that of shawwal any that's any 6 days in the month of Shawwal), one can do qaza and one would automatically get the reward of that specified day if one has intended it as the aim is to spend that day in sawm, so just like how if one spend the nights of Qadr in doing Qaza salaat, one would get the reward of spending the night in ibaadah as the aim is to fill these auspicious nights with ibaadat. Please explain with reference.