Due to the nature of Scottish records, you are at the stage where the vast majority come to a halt. The reason for this (as you'll be aware) is that very few marriage records from this period name parents, and if the person died before 1855 then any death record will not name the parents either. So even although you THINK you may have identified the correct birth, you will be unable to prove it.
The reason I say "the vast majority come to a halt" and not "they all come to a halt" is that occasionally proof exists from other sources (a will, sasine records, a multi-generational gravestone, a family bible etc), but these are very much the exception rather than the rule, and most often only apply to very wealthy families (a very small % of the population).
You should take with a pinch of salt those who claim to be able to prove their Scottish ancestry back into the 17th century or further. They are very rarely using primary sources, and are often just copying inaccuracies which have been previously recorded by someone else. I often ask on the forums where the proof was obtained from, and almost without fail no such proof exists.
One of the most common errors is the assumption that because only one person of a particular name is shown in the Parish Record of Births in the relevant area then it "must be him". But not all Parish Record of Births were recorded in the first place, and of those which were recorded, not all have survived the passage of time. The further back in time you go, the higher the % becomes of those for which no parish record exists.
So my advice for you would be to go down the other branches of your family; or widen the search to find out what became of siblings, bringing the lines of those who remained here FORWARd in time; or use internet resources to find out more on where/how your family lived etc. It's a never ending jigsaw !