As a
general rule, most schools do look at the individual scores because they do want to make sure that you didn't have a huge skew. For example, a Q37 V50 will get you to 700. V50 is an amazing verbal score; Q37 is significantly weaker.
Most of the top schools (ie, the ones that have 700+ as the published average or median) are looking for at least a 45+ on Q and a 36+ on V. Note, though, that a Q45 V36 combo would not actually get you to 700—it's only about a 660. So you have to score better on at least one of the two sections in order to still get into that 700+ range. If you score below Q45, they may be concerned about your ability to handle the quantitative work in their program. Ditto for the verbal score.
The expectations can also change a bit based upon your educational background, though they don't talk about this as much. They're likely expecting most people who did their university studies in English (and are hitting 700+ scores) to score higher than 36 on Verbal. For those who did their studies in a language other than English, though, V36 is good.
Another example: A score of Q45 is around the average for someone who was educated in North America but is below average for someone educated in China* or India, so if they see a Q45 score come in from someone educated in China, it may be the case that they look for other factors to ensure that that person's quant abilities are strong enough for the program. (And ditto for the did-university-studies-in-English folks I mentioned above—they might look at the essays more carefully if that person is scoring on the lower end of the range for V.)
*I don't know whether this is still accurate, but I saw a stat maybe 5 years ago that the average Q score for test-takers who take the test in China was something like 48 or 49. The
average score! Color me impressed.
So to your final question: If someone's scoring, say, Q50, then you could hit 700 with about a V35...but I'd be aiming for V37-38 (which still gives some buffer room to hit V36 even if the person falls a little short).
If you're trying to hit 730+ and doing well on Q, then you'll be fine on V (if you have Q51, then you have to hit at least V38 to get 730). The person who would have to be careful in this case is someone who is doing better on V. You could score V50 and then you only need Q41 to hit 730—but that Q41 is likely not going to be good enough for the kinds of schools that are looking for a 730 score.