Annulment - Question on venue and what happens to payment to law firm if case gets dismissed?

Hi, I have a few concerns regarding my filing for annulment and I hope for your advice before I engage the law firm:

1. Background Information:

I was married in Pasay, I worked and lived in Pasig before my wife and I separated last year and now we both now live in QC. She lives in a house that we both own and I am sharing a house for rent in QC.  My ex wants me to turn over that house to her.  I also have a residence in Mindoro where I go several times a month and which I consider as my permanent residence because I have been slowly building this house for years on a leased lot that I intend to buy (unlike in QC where I am just renting).  We are also in the process of selling our property in Lipa and that is something I would like to settle along with the annulment case because she has threatened to take all the payment from that property (She has been directly dealing with the buyer).  I would like to file my case in Mindoro (my lawyer advises Calapan or Roxas would have the family courts)

2. Questions on Appropriate Venue:

Can I file my case in Mindoro as my lawyer advised and is there a possibility for my ex to contest the venue and have my case dismissed because of this?  If the annulment case is allowed in this venue, will the court also have jurisdiction to rule on our Lipa and QC property issue?

3. Question on Payment:  The law firm is asking for a lump sum payment - half up front and half after the case is finished.  If I do engage this firm which is based in Mindoro, and my case gets dismissed due to the venue, will I lose the entire amount that I pay upfront, then have to start again with another law firm based in wherever the court deems as the proper venue?  

Many thanks in advance for your advice.

You can file wherever you can, as long as you had stayed/lived there within (Philippines) the past 6 months (temporary or permanent) or can prove a residence of stay on that place afaik whether in Luzon or Mindoro. This can be your place or her place as spouses, where one spouse resides or stays.

If your annulment includes separation of property regime on that annulment case, then it will be discussed on that court. Depends on the grounds, the law on separation of properties will be applied. If your case is about void marriage, then co-ownership law. Otherwise if its voidable marriage, then conjugal ownership will govern your property claims. The later one, can be fairly distributed between spouses in court imho while the first one, a contribution must be proven. Once a court decision (final decree) is reached and declared, necessary notification on that to concerned institution/s can be done and updated like NSO, RDs, local civil registrars etc.

#3 Your atty can answer you on this. Try asking your atty.