My Dear Friend,
Please Do not panic.
What are the allegations made by your wife against you & your other family members in her 498--A, 323, 504, 506, 377, 354-A & 354-B application, defeat / destroy them by doing thorough research in collecting information, documents, evidence etc., against her alleged allegations.
Go all out in defeating the said allegations with documentary proof.
What are the contents of FIR try and defeat the contents as stated above. Your duty for now is to collate information, documents and/or evidence to defeat her allegations and also the FIR alonwith the findings of Charge Sheet (if the same is filed). You can also go for Quash of the same.
No need to respond to the Police when they call you. Politely tell them that since FIR is filed case is sub-judice before appropriate Court, handle it diplomatically. Further, keep record of all the calls you receive from alleged Police people for further reference & use.
In response to contents of your post:
Police has no authority to take law into their hands and make settlements. Their domain is restricted once they file FIR / Charge Sheet. You may claim in your defence stating that, upon duress, force, undue influence and coercion you had paid the first chunk of money and signed documents in Police Station (you need to prove your version, beware !!!) as far as, the second chunk is concerned you can protest and need not pay the same. Share the T & C of your alleged MCD document.
In response to contents of your post about second motion:
Since your issue is sub judice before appropriate Court, avoid to meet them diplomatically. You write to them under acknowledgement refusing to meet them on above ground, make sure not to provoke them. Your diplomacy will come to your rescue. All payments / settlements (to be made through Bank only) to be done before court of even jurisdiction before which your case falls, till then avoid one and all diplomatically without causing any nuisance.
May God Bless You Buddy.