Paroles would be number one on the list of influential people in Bertram's life. If you've been paying attention, you know that this is not a good thing. Paroles is one of the biggest jerks in all of Shakespeare. That's why Bertram's mom is always saying that Paroles is a bad influence on her son.
The older generation is always sticking their collective nose into the business of the play's young people, don't you think? The countess, Lafeu, and the king of France are constantly dispensing advice and they basically force Bertram into a relationship he's not ready for. Why is that? Well, they seem to think the members of the younger generation (especially Helen and Bertram) aren't capable of making their own decisions. We should also point out that the King is Bertram's guardian and the countess is guardian to Helen, so from a legal standpoint, they have a right to meddle in the affairs of their young wards.
Come to think of it, this is classic Shakespeare. In many of his comedies, parents and guardians are always butting into their kids business. Here are just a few examples:
Check out Polonius' "To thine own self be true" speech to his son in Hamlet. (It reminds us of the countess's speech to Bertram.)
Compare and contrast how the Capulets and the Montagues (and even Friar Laurence) get involved in the love-life of Romeo and Juliet.
Remember how Portia's dad orchestrates his daughter's marriage (from his grave) in The Merchant of Venice? Not so different than how the king of France forces Bertram to marry Helen, we'd say.
We could go on, but you get the point.