1. Yes she can claim maintenance under DV act. If she files for DV it will be maintainable. There is no time limit for filing such cases. She can file as long as she is your legally wedded wife. Just like she lodged 498A on you after 2 years, she can file the DV case after 4 years.
2. DO NOT FILE FOR DIVORCE when 498A is pending. Let me tell you why you should not file for a Divorce when 498A is pending. Divorce is a civil case and 498A is criminal case. Both have no dependency on each other. You cannot stop 498A just because Divorce is pending and vice versa. Let's say Divorce is granted, then you will have no hold or leverage against her. She is free to remarry. She will happily remarry and you will still have to fight with 498A. Although you are free to remarry, the probable alliance will have to think twice as you can still be convicted in the 498A case.
Suppose you have a girl waiting to marry, then it makes sense to file for a divorce. But if this reason of yours is let out to your wife, then she will ask for huge alimony as she knows that you are in a hurry.
Suppose she is in a hurry to remarry, then you clearly have a leverage on her and you can say that you will give Divorce only if she agrees to the condition that you will give alimony amount pertaining to only your son's expenses and no alimony to her and provided she withdraws the 498A and other complaints.
3. She can claim the maintenance under HMA 24. She will give some or the other reason, and say her situation has changed now, etc. and will try to convince the judge. Everything is different provision of law and each one has no bearing on the other, provided she has already been awarded maintenance under any provision.
4. You can approach the HC. But most likely it may not be considered as it's just 2 years and you are not in prison. Speedy trial usually has more effect suppose if someone is in prison. But you may give it a try.
6. She cannot reopen the 125. From my understanding she can file a fresh 125 as right to maintenance is continuous right.
7. NO. Already answered in depth in 2.
Having answered your question, here are my suggestions:
If you are wanting a Divorce, send a Notice to her to come forward for a Mutual Divorce. She may consider and come. Suppose she doesn't come (wait for another 3 months), then file an RCR.
Regarding your 498A, file a discharge application, instead of going for Trial. Also, why don't you consider approaching HC for quashing of Charge Sheet under 482 instead of Speedy Trial?
First file 482 and then discharge (if required).
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