use of present progressive, contrasting with simple present

I want to know if the following sentences are correct, taking into account the use of frequency adverbs (usually, sometimes,....) and the relative pronouns (when,....)

Here I go with the sentences:

When I SEE him, we always GO to a pub

We usually MEET when we Go to work

What happen with "when" here that always evoke precise action with simple tenses?

Paul and Tim go to London three times a year, but next summer they ARE STAYING/ STAYS at home. My doubt here is what happens with those verbs which refers to an state and they doesn't have a beginning or an end?

Occasionally he GOES to the cinema, but he GOES to the cinema at least once a week.

Susan HATES potatoes, because she THINKS/THINKING they ARE bad for her.

Sam can't go to Mexico next summer, so he VISITS/VISITING his grandmother