OK, reading it again I sort of see what you were trying to say but it is confusing to have written Ab (meaning the key of A flat major) twice when you were trying to demonstrate how to get to A major. It is also not completely accurate to say that a key signature of F# C# G# represents A major as it is also F# minor.

B becomes problematical

Doesn't need to be. I can't see why fiddling in 'folk style' should mean confining yourself to first position. If capos are 'permitted' on fretted instruments, why ever take any notice of a 'taboo' on moving up the fingerboard?