You can file wherever you can establish that you or your spouse are domiciled for purpose of jurisdiction. It would make sense if you and your spouse would agree on a location. If you are in agreement as to the division of assets, you shouldn't need ancillary proceedings in other jurisdictions.
The amount of time it takes to resolve a case depends on the jurisdiction. Waiting periods vary by state. A court's docket can vary by county and judge. Your own diligence in pursuing the case, and avoidance of any errors in (apparently) representing yourself, plays a role.
If you want to sell your home, you can agree to sell your home, now or later. What do you want to do?
If you sell the home and pay off the mortgage, your spouse will have no further liability. If you keep the home with her quit claiming her interest to you and refinance such that she's off the mortgage, your spouse will have no further liability.

