1 The final verbs in the underlined phrases are in the Past Simple, except for 6, which is Past Perfect.
2 as were
3 How about
half-baked: not well planned or considered. E.g. a half-baked idea
live up to something: to do as well as or be as good as other people expect you to. E.g. He failed to live up to his parents' expectations. The team called ‘The No-Hopers’ certainly lived up to its name.
5 want that
come up with something: [no passive] to find or produce an answer, a sum of money, etc. E.g. She came up with a new idea for increasing sales. How soon can you come up with the money?
7 one time
1 It's high time you spoke to your mother.
2 Suppose I pressed this button, what would happen?
3 They treat that girl as though she were a princess.
4 Given the choice, I'd sooner learn Chinese than German.
5 What if there were a volcanic eruption in a densely populated area?
6 It's about time she stopped smoking.
7 They behave as if they own/ owned the place.
present: they do
past: they don't
8 I'd rather you didn't go there.