native speakers view on the meaning of the modal words "could" and "might"

How does a native speaker of English understand the meanings of the modal words could and might in sentences (present or future tense, not past tense sentences) without a specified conditional clause?

a) a word with a conditional meaning like the modal word would

OR b) a word with no hint of conditional meaning.

A few sample examples are shown below ( sentences without a specified conditional clause):

1) It could be true, but I'm not sure. 2) We could go to the cinema. 3) I could stay with Sarah. 4)I could go with you to the supermarket, but I'm not sure.

5) It might be true. 6) you might want to consider quitting your barista job. 7) You might say that, yeah.

The above is not an exhaustive list though.

Note: "A word with a conditional meaning" means when you hear the word would/could/might, does it sound like there could be a conditional clause, although you don't add one or rather you don't need to add one? Because, I see would expressed in conditional form all the time.

Solution 1:

(1) shows a modal usage (ie one commenting on the possibility / probability of the covert statement ['It is true']) ('but I'm not sure' is another modal qualifier) (and sorry about the dual usage of the term 'modal' here).

(2) is probably just a hedged (and slightly less enthusiastic) variant on 'I've a good suggestion: let's go to the cinema'), though if 'could' is emphasised, it might be a counter to 'We're not even allowed to go to the cinema'.

(3) is probably just voicing a possibility, though as in (2) it could be a contradiction, of 'You're going to have to leave now to make your appointment tomorrow' say.

(4) is unacceptable. Perhaps 'I might be able to go to the supermarket with you, but I'm not sure' is intended.

(5) is voicing a possibility.

(6) is an idiomatic polite form (though it might be being used with mild sarcasm). The non-sarcastic usage is a hedged form of 'I'd really advise you to consider quitting your barista job.'

(7) can be used at various levels. Context is critical here. It can range from 'I hadn't really considered that, but you're right' to 'Don't be stupid, it's as plain as the nose on your face'.

But modals (the 'modal verbs') are used in a bewilderingly complex array of ways. I seem to remember that OED has about 14 pages on 'should' alone.