just last if not ok(...) ahead of any dependent tests

That breaks the test plan, which you are correct in saying that it doesn't have a lot of value, at least from a development point of view. However, it also has some value when your boss comes to your cube and asks what you're up to :)

Even so, some of the other posts show that skip doesn't have to be nested at all, which works out the same as last if not ok but maintains the test's plan.

There's also no harm in having more than one test script for a given module.

In this case, it's a CGI::Application program and each page returned is strongly related to what was filled into the previous page's form.