Dear Concerned,
Lets Understand these issues step by step
a. You have filed divorce in USA and you may be able to get an Ex parte degree which is not an issue but you can not claim the validity of same here in India as this is an exparte decree.
b. Your and your fathers property - your wife can not claim any rights on either your or your fathers' property except those property which you might have bought in joint name with her. So you need not to worry on the same
c. PLEASE note that yes you can file matrimonial cases in India with your wife but for that you will have to be personally present . HERE is what you should be thinking and doing ----
c.1 DO NOT come to India - if you come to India and your wife files a false complaint against you and your family it would be difficult for you to go back .
c.2 Your parents should file a complaint in the nearest police station of the threats being received by your wife and her relatives and also make sure that she does not comes back to your parents house - please note that your wife does not have any rights to forcefully stay or enter your parents house.
c.3 Alternatively you may choose to call your parents to you in USA for some time - just ignore your wife - SOON you would notice that your wife will start following up with you and will like to settle the disputes amicably.
c.4 only issue which i see is her extended visa she may come to US to you and might create issues there. This can be handled easily as well - for this you need to give a complaint / information to the Police Help near you thatyour wife left on so and so date and as there are differences your wife might come back and file false complaints against you. This would help at later stages.
Summing up - DO not come to India - ask your parents to file a complaint or call them to US to you.
Best of Luck