AE store visit, online sizing guide and the Long Branch: Looking for advice

Trying to make a valiant attempt at getting my Long Branch order from AE correct the first time! The nearest AE store is 2.5 hours, and I actually went there yesterday. While the sales associate that assisted me was friendly and all, there was not "Master Fitter" feel to it whatsoever. I asked several questions regarding length and width concerns with few answers and little guidance. Here is my short analysis followed by a couple questions:

• Tried the Long Branch (in the dark brown pebble) in a 10.5 D. I seemed to have enough toe length, but felt just a little pressure on the width. The ball of my foot seemed to fall the smallest amount behind where I assessed the sole flex point to be. Some heel slip when I walked, but I assumed that would settle down after break-in.
• Next tried the Long Branch (in the golden brown chromexel) in a 11.0 D. I had plenty of toe length, maybe just a tad much yet ok, and the width seemed fine. No width pressure, but I did feel like the volume of the boot was a little too much. I expected I may have to cinch the laces pretty tight to get a proper fit. The ball of my foot seemed to fall just a tab bit forward of the sole flex point. A little more heel slip than the 10.5 D, but not a great deal of difference.
• Then tried the Wilbert shoe (same last - 511) in a 10.5 E. The store did not have any other width than D in the LB. Seemed to fit fine, though I probably did not spend enough time evaluating. Was not sure if evaluating the last in a shoe would be the same as the boot.
• Today, I printed the AE fit guide and measured my own feet. Wore a regular casual cotton sock (not a thick sock, not athletic). Ended up at 11 length and a W7 width measurement indicating a C width. The AE sales associate measured the same length with the in-store device with my width falling between a C and D.

As I expect many have as well, I have always worn shoes offered in a D width since that is "average" and available in stores. With the cost and longevity of AE, I kinda want to get my best fit possible. So:

• Can any of our AE shoe experts zero in my experience above to what might be going on with my sizing? Am I approaching my fit correctly?
• Can I/should I just trust the AE sizing guide (corroborated by the in-store device)? Should I order the 11 C? Would the C width trim down the volume from the D?

Thanks in advance for any help!

AE store visit, online sizing guide and the Long Branch: Looking for advice