Using video calling to communicate with deaf people

Q: The reason I'm writing this mail is to know a clarification. We have a lot of Muslim deaf brothers all around the world especially a lot of effort is being made in the field of Tabligh among them in our country (Sri Lanka). The only way they can communicate with other deaf brothers is by doing a video call when they are at home or work (because they are unable to speak/hear so we need to use sign language to communicate by video). Since the video is not reproduced (it's just a live stream) and the objective of the call is to discuss an important matter - would that render video call permissible? (By no means do I consider the television streaming permissible but I would like to understand the point of video call at this point because it's vital). 

Finding out the qiblah direction

Q: Me and my father were in a new town at the time of salaah. My father used some kind of compass and found the Qiblah direction. The next day we found the Qiblah to be different, as my father made some kind of mistake or the compass didn’t work properly, maybe 90 degrees in different direction was what we originally faced. Must the salaah read in the wrong direction be repeated? 

Ma'zoor

Q: I have a discharge problem and I fall under the category of mazoor. I have a few questions

1. Do I need to make istinja for every salaah?

2. Do I need to change my panty liner for every salaah?

3. I'm pregnant and I have a gas problem, will passing wind break my wudhu?

4. If I'm making tawaaf and I pass wind. Will I need to remake my wudhu?