It's very subjective as to what constitutes a hard game. For example, RC is by far my worst section, but I usually go -0 or -1 on the "hardest passages," but miss 3/4 on "easy/medium passages. It all depends where your strengths and weaknesses lie.
This is basically my life's work, convincing people of these things ... Except the cold shower. Ain't got no time for that, and if you're supporting your adrenals otherwise, you won't need to.
Blood, sweat and tears.
You need to work on LG. Getting -0 in LG will likely put you in the low to mid 170s. Complete the logic games bundle and use he fool proof method.
One of the best things about the LSAT is that you can approximately predict your LSAT score via timed PTs. If you are not consistently hitting around your goal score, postpone -- unless there is an urgent reason not to delay applications.