[Moving variable data text fields depending on size of graphic]

How about making each address block graphic an inline graphic in the same text box as the phone number?

[Imposition, and Shells, and Reader Spread]

I see what you're saying, now - I actually tested it out and I am not getting what I expected, either. I probably should have tested it first before offering the solution.

[Imposition, and Shells, and Reader Spread]

I had told FPI to expect a 2-page document (under the Document tab where it asks for Pages Per Record) with the thought of deleting the unused pages and selecting Simplex as the layout.

 

I don't know how to achieve what you are after and still leave all 4 template pages, unless there is a way to specify to only output 1 side during Compose.

 

I wonder if there is a way to tell your output device to only output odd pages. If so, you would simply compose the whole thing without suppressing 2,3 and simply tell the RIP or printer not to print even pages.

[Imposition, and Shells, and Reader Spread]

Could you remove impressions 2 & 3 from the document itself (since they are already preprinted on the shells)? Then make your imposition a 2-page simplex (see screenshot.) Instead of 4&1 it will be 2&1.

[Multiple page PDF]

Can't help with #1, but for #2 you can select the text frame that will contain the placed PDF, and in the Text Frame palette click on Overflow and change the setting for Add Pages to "So Last Added Page Is Even."