Help needed with the next steps on my preparation

Hi,

During my first GMAT attempt i got 660 (Q49V31), second attempt was even worse (Q47V31), despite the fact that i focused on the V between these two attempts.
My goal is 700-710, so i'd like to improve V from current 31 to at least 39 points (need to have some room for Q score fluctuations).

The problem is - i cannot spot exact weak areas in my V, and there's no competent tutors in my city to help identify my problematic areas and create "useful" study plan: right now i feel like i'm doing SCs/CRs randomly here and there, but not focusing precisely on what needs to be improved.

I have used Magoosh and some old OG/MGMAT, but during that time i didn't have an error log, so i'm kinda lost where to start from now...


So i would really appreciate if someone could help me with the answers for the following questions:

1. During my exams, i got 14 or so incorrect V-answers, evenly spread among SC/RC/CR. Now I would like to focus on the SC first because:
- it will improve my score itself;
- it will greatly reduce the time spent on SC -> i will have more time on CR (i'm doing CR pretty well when spend slightly more time);

2. Is there any online source/test with detailed diagnostic test that will show exact gaps in my SC? For example, Magoosh has "Subject" column in its Review, but it is pretty high-level (8 types of SCs only) - i would like something more detailed so i can setup my study plan;

3. Should i try additional resource (for example, E-GMAT - it seems that the E-GMAT's explanation of grammar is more understandable for the non-native speakers than other sources' materials) and finally create an error log, or doing Magoosh/OG/MGMAT again with an error log should be enough?

4. Is there any specific set of skills tested in SC/CR for the scores V31 to 39? For example, as far as i understood, CR bold-questions appear at ~V35+ only - is that true? Or they appear in the higher scores and i shouldn't be bothered mastering them and instead focus on other things?

5. I know that the GMAT score calculation is a complex thing, but what is the approximate difficulty level of the Gmatclub's topics that corresponds to the V39? 55%/65%/75%?

Thanks in advance for your help!