Facing Master Pages, how do I make them reassign themselves to left or right when I add an odd # of pages?

Question

I've been designing a travel journal & photo book series, and my process is that I have Master Pages A-D, facing. I'll put in all the text (Masters B, Left and Right), then I go back through and insert the photo pages between the correct dates. This generally works fine when I'm adding an even amount of photo pages, but if there happens to be an odd amount of photos for a specific date, then in shifts all the following pages so that instead of the two facing pages layouts being LEFT/RIGHT, it shifts to RIGHT/LEFT:
This is how it should look (LEFT/RIGHT):
But then if I add a right-oriented photo page, like this:
it them shifts everything following it (RIGHT/LEFT), like this:
At first, I thought it was just the text pages, because the design requires every text box on a LEFThand page to be centered, but the RIGHThand ones to be left of center, but If I add a LEFThand photo page inbetween the two incorrectly oriented pages in the previous photo, the photo page does the same thing:
While doing this fixes the pages following it (because it's now an even amount of pages that have been inserted), I don't understand why inserting a RIGHThand layout into a RIGHThand slot doesn't correct it. If I drag the Master Page INTO the page (as opposed to adding a page), I get this dialog box:
(note: this does NOT happen if the orientation of the facing pages is the correct one) I looked at every page's size and page setting (via page tool), and they're all the same:
MY TWO QUESTIONS:
1. Why does this happen and can I fix it/keep it from doing that?
2. Is there a way to select an option or something that shifts everything so that if a text page starts as a LEFThand page, but then gets shifted over one, it'll change to a RIGHThand page? (I'm using CS6 for Mac Snow Leopard)
Thank you so much!

Answer 1

Why does one page have a different orientation than the others? If it is printed, you should keep all same size and orientations, exceptions only for pages which have different final sizes!
You should set up you margins on the master page according where the text frames should be. But your frames are somehow laying on your pages without any relation to the margins borders.
When you add an odd number of pages—it doesn't matter how—, it will shuffle succeeding left pages to the right, right pages to the left. That is how it is, except if you keep spread together or you don't allow to shuffle pages.
If you want to adjust the content from a left page to a right page layout and vice versa you have to use either Layout Adjustment (correct margins are VERY important) or the new Liquid Layout Concept, good descriptions to learn this complex thematic are in the manual and in linked tutorial movies.
If you insert a page based on a master it will use on the left side of a spread the left side of the master's spread and on the right side of a spread the right master's spread, if you grab the left or right side has no influence.
Another influence comes from your text styles, used in keep options in paragraph styles. There you can determine that the paragraph style forces a headline to the left or to the right. Important with headlines in longer layouts.
You should give your master more identifying names, not A-Master, B-Master, but like TIT-Titel, STA-Standard, but this is not the main problem here.