It's 'glass noodles' not 'grass noodles'! They're called that because they are very fine and transparent. Here's the wikipedia pages for 'cellophane noodles', which is another name for the same product. And on a grammatical note, remember that it's 'some stuff', not 'a stuff' - 'stuff' is an uncountable noun.
'on sparkling form' means the same as 'on top form'. A student who is getting all the answers right or a sportsman who is scoring all the goals could be said to be on 'sparkling form'.
'a domestic' in the sense of quarrel/fight, say between a husband and wife, comes from police detective slang. The police need to note down what type of incident they have been called out to deal with, and 'a domestic' is a shorthand form of 'domestic incident' or 'domestic dispute' or some similar phrase. This means that it's a family affair, not involving any members of the public.
Just wondering if the same term would be used by American police or not?