Switching work to spouse extension

Hi all, I'm changing my 'reason to stay in Thailand' from employment to Thai spouse. Had my WP and previous extension cancelled yesterday. I'm now on a 3-week extension which is apparently intended to give me time to either make new arrangements, or leave. It ends February 18th.

Been reading various sources on getting the spouse extension because I want to do this right. But I have a few questions.

1. I read that it takes 3 weeks to receive a decision on the spouse extension. I also read that to accommodate this time, I'll get a new stamp granting either 30 or 45 days at the application date if my paperwork seems in order. I am currently already on an extension that aims to accommodate new arrangements, but it's only 20 days. It just feels a little odd to me if I get yet another stamp with such purpose again, but it seems that I do need the extra time. Is this indeed what happens? Or should we apply asap?

2. We took photos in normal everyday clothes (shorts, t-shirt) to show how we live. Found a source later that we should have dressed more formally. Seems a little odd to me because we really just show how we live, as they request, so why would we wear clothes that we normally don't? Should we retake the pics? Appreciating your viewpoints.

3. Applying at Cheangwatthana immigrations. Taking the whole family, who prefer going in the afternoon. Any recommendations on the time to go? Been reading varying recommendations. If necessary I could go early myself to get a queue and have them come later.

4. Looking at the future: if I get this extension approved now, and I'm not in Thailand next year around this time, am I right that I can't extend it and need to do a non-O at an embassy?