Not sure how you separate Modern Scots from Laland Scots and don't want to offend.

Tell me if I go wrong - the Gaelic of the Highlands and Islands is Erse.
Nobody knows anything much about the Pictish language other than the names of their kings, kingdoms and placenames.
Burns wrote in Scots and many of the his words are derived from Norse eg bairns, burns and byres. If any Gaelic has influenced Scots, then I am ignorant of that as I know nothing at all of Gaelic.

Back to Maeshowe - could there be a link with Maes and Irish personal name - Maeve? Seems unlikely to me. Was Erse ever spoken in Orkney?