The word order DOES play an imortant role in Russian, especially in written form, where you cannot hear actual logical stresses. In written Russian what is known (linguists call it "theme, thema") usually goes forward, and what is new ("rhema") goes in the end. In spoken language the order is often absolutely inverse, people tend to tell new and important information in the first place, but there are intonation sresses also.

So
Студента могут мотивировать только деньги. It means that Only money may motivate a student (not busienessman, worker, teacher etc.)

Только деньги могут мотивировать студента = Only money (not a promotion, interest or whatever) may motivate a student.

Мне не нравится твоя фамилия = I don't like your family name.
Фамилия мне твоя не нравится = spoken intonation, something like Your family name...well, I don't like IT!