While many people complain about the "tones", I feel this excuse to be widely overblown. For Americans, Mandarin phonetics, with a few exceptions, are actually quite easy. Plus, if you default to the first tone (flat) all of the time, people WILL understand you in context. Let's take 城市 (city), and 诚实 (honest), for example. If you want to ask someone where they live, it should be patently obvious that your intention is to use the first word... vice versa also applies.

One nice feature about the spoken Chinese language that those who haven't studied it often don't realize is that the grammar is incredibly simple... predominantly subject-verb-object, with little concern about verb tenses or pluralization.

This means that if you have 100 nouns, 50 verbs, and 50 adjectives (which are often constructed based on nouns) under your belt, you can get by quite well.

That having been said, I don't think 7 hours of study is likely to get most people very far. In fact, I sunk 4 years into the language (high school, mind you) before I ever set foot in China, and found myself grossly unprepared to communicate with the locals (there was a huge disconnect between the stuff in my textbooks and how people actually talked to each other). Basically, all of that fancy grammar they taught us proved to be useless in practice (I never aspired to write Chinese novels).