Grammatical grizzles

I am irritated by some common mispronunciations and use of words and sayings, which while they may be technically correct, are instances of careless or lazy elision. For example “the proof of the pudding is in the eating” not “the proof is in the pudding”. The word “mischievous” should not be pronounced as though there is a non-existent “i” after the “v”. Why say “agreeance” when “agreement” is more mellifluous and understood by all. Why cannot I, born in New Zealand of parents also born here, not refer to myself as an “indigenous” New Zealander? I consider myself a native of New Zealand just as much as anyone else born here. Peter Clapshaw, Parnell