Does this verb always take an indirect pronoun (le, te?)
E.g. The speed at which he speaks makes it difficult to follow him?
(Please translate the above sentence colloquially.)
Is hacerse difícil the same meaning or is dificultar stronger?
La velocidad a la que (él) habla hace difícil seguirle.
Perhaps "hacerse dificil" is a little bit more colloquial than "dificultar" but it can be used both colloquial and formal. You will find "dificultar" in written spanish more than oral. But I think you don't need to worry about that.