means 'the yearly recurrence of the date of a past event' (Macquarie). So first anniversary, 21st anniversary and so on. Not '10-year anniversary'.
you can't fight it—it's language change in action, driven here by online gaming. So we can say goodbye to any distinction between alternate and alternative as outlined here. In popular culture at least.
and it's phenomena (plural) but phenomenon (singular)
means caused by, not 'because of'. So 'The delay is due to [caused by] bad weather' is correct. 'Due to [caused by] bad weather there is a delay' is widely used but 'Bad weather has caused a delay' is considered by some to be better usage.
a choice between two (bad) alternatives, so shouldn't really be used to describe a general problem, as in 'When parents go back to work they face the dilemma of working out who's going to look after the baby...' Anyway the sentence is too wordy, and is better as: When parents go back to work they need to decide who's going to look after the baby.
means where two points meet. It doesn't mean on the verge of. Your birthday can be on the cusp of two star signs, but you can't be on the cusp of adulthood.
this means to evade the issue (strictly to assume as the resolution of an argument the point being argued). It does not mean to raise the question, as in 'that raises the question of whether politicians should get funded study trips at all'. So when you mean to raise the question, please use raise, not beg.