Not sure why you want an extra button, SAP takes care when you save, based on the settings made for info update indicator and the SAP special programmed logic (which was numerous times subject to questions - please search in SCN - there is even a FAQ SAP note on that)
What would you call it if you give your son a shopping list with 4 items and he comes back with the first item only ?
I would certainly not think that this is the expected behavior.
Hence you have to analyze why this happened.
And as you already pointed out: "I have two basic queries."
You can certainly find endless discussions on ME59N and even 43 which talk about a check report, hence search with this term: me59n check report