In terms of whether 740 vs. 720 will make a big difference on your application, you really need to talk to an admissions consultant, not a GMAT expert. :) We have a folder here called Ask An Admissions Consultant and you can also find other places to ask admissions folks, so go do that and tell us what you hear.
I do note that you broke the 80th percentile on verbal, which is a plus for your demographic - but, again, talk to an admissions consultant.
In terms of whether you can raise your verbal - yes, it's possible with quality work. I can't tell you whether the E-GMAT verbal course will work for you - I have never used it (haven't heard of it), but it sounds like you've used it before so, if you like it, go for it.
I do have to note, though, that "many more mock GMATs" is definitely NOT the way to go. You don't learn much by taking practice tests. You learn *between* practice tests, when you're analyzing problems and your thought processes and etc.
Read the "how to learn" section of this article:
http://www.manhattangmat.com/blog/index ... an-part-2/Are you actually studying in this way? If not, then that might be why your verbal score has stalled out. Doing tons and tons of problems, without really diving in to analyze how they're constructed and how you need to think them through, will only get you so far...