Here's a wild shot at your word pairs without doing any research.  Of course there are special meanings in special fields.

1. "Collaborate" usually describes people working together as equals on some project.  Members of the team collaborated on designing the new defense.  "Cooperate" more often describes unequals.  I try to cooperate with my boss.  The witness cooperated with the police.  There are many exceptions.  Those who cooperate with occupying forces are often called collaborators in a pejorative sense.

2,  I think of "extend" as linear and "expand" as three-dimensional.  A balloon expands; a tape measure extends.  The mayor plans to extend the rail line to the coast.  The newspaper plans to expand its coverage of the election.  The deadline for filing taxes has been extended.  As a nice exception we have the coefficient of linear expansion, which describes how much a bar of steel extends when you heat it.  (It also expands in its other dimensions.) 

3.  Not so easy.  The old telephone operators used to work at the telephone "exchange", but on the freeways it's an "interchange."  When we say two automobile parts are interchangable we often think of  both of them as being good.  But we would exchange a good one for a bad one (or a bad one for a good one).

4.  I think of a "tourist" as someone who goes to see the sights while a "traveler" usually has another purpose, such as business.