Pronunciation questions

In fast speech, which sound is often omitted at the end of the first word in a question tag such as 'isn't it'?

Which word has the long /iː/ sound?

Which pair shows the difference between /iː/ and /ɪ/?

Words that do not carry the main message, such as 'than', 'and' or 'at', are usually pronounced with the weak vowel .......... .

In the adjective 'dangerous', the unstressed suffix -ous is pronounced .......... .

In word families the stress can move. In the word 'photographer', the main stress is on .......... .

In the word 'technology', the main stress is on .......... .

When speakers contract past modals, such as 'might have' → 'might've', which sound disappears?