OP you were given a tough time at the start of this thread, especially given you were just seeking knowledge! I hate when Mumsnet gets aggressive, it puts people off asking things in the first place.
In answer to the Neeve/Nee-uv thing - it's partly down to accent I suppose, if you listen to some Irish accents it'll become more clear - I don't know if you're acquainted with - the wee girl on that would pronounce it Nee-uv, but a lot of Niamhs would say Neeve.
The Scots thing - it's a language and has many different dialects within it. This website is great, it gives you loads of info about it and gives you lots of soundbites to listen to.
Luna I agree that there's a load of similarities between English and Scots but that's a particularly English excerpt you've chosen. In the same poem you have:
But Tam kend what was what fu' brawlie:
There was ae winsome wench and waulie,
That night enlisted in the core,
Lang after ken'd on Carrick shore;
I doubt my English DH would have much chance of understanding that! Awesome poem though, my favourite Burns. I'd also agree that sadly there is a class element involved in the use of Scots. My parents generation often received the strap for speaking in Scots at school, which boils my piss as not only is it a fantastic, very expressive language but it's part of our culture and when you look through the generations you hear a marked difference in the dilution of Scots. My great grandparents spoke either Gaelic or Scots (depending on the side of the family) but none of my generation speak Gaelic (something I hope to change one day) and only four out of 13 of us understand broad Scots, six of us use Scots mixed with English in every day conversation and the rest might recognise words like 'wee' or 'bairn' but that's about it. Most primary and secondary schools here teach some Scots poetry, secondary schools study Scottish literature (ironically as part of the English curriculum) but this isn't necessarily written in Scots, just by Scottish authors.
I would absolutely recommend reading some of the Scots versions of the Julia Donaldson books - here's a link to the Gruffalo being read on YouTube!