Set aside lumpsum money in your wife's name as FD.
My observation is that 498A has lost its tooth since Supreme court ruled No immidiate arrest. Atleast this fact is true in South India. There are various anecdotes available.
Be firm and keep a lawyer present in all meetings with police. Police station or CAW whoever invovled can only prepare report and submits to court. Don't offer bribe or any other activites. And hopefully you have not mistreated her in anyway then case won't stand on its merit. At this point move to court to quash and If report is against you then take Bail and so on.
You need to be separated for a while before divorce case can be submitted. And if you win 498A or case is quashed then you will have grounds for divoce on cruelty.
But by nature, if your wife in advance trimister, she will not be able to take this running around. Let baby be delivered (take care of hospital expenses even if it is cesearean). Usually pregency to motherhood women are preoccupied anywhere between 15-20 months.
Who knows what happens once baby is born.
The rest of your queries are too presumptive and too early for any suggestion