Since no one else has answered you I figured I would give it a go. The main problem with creating a central account page is that different php files are referenced. For example, I created a your_account.tpl that I cloned from menu_cart.tpl that "appears" in the menu column by enclosing it in an "if" statement when a customer is logged in...
Code:
{if $login ne "" }
{include file="customer/your-account.tpl" }
{/if}
in skin1/customer/home.tpl. It has "Modify Profile" "Delete Profile" and "Order History" as choices the customer can make. Each of these is nothing more than a link to the php file that does what the customer wants to do, but it works well for what we need. Modify and delete both use register.php, and order history uses orders.php. Adding newsletter subscriptions would be even more complex.
I'm not sure how you would go about calling each of these php files on the same page but I see no reason it could not be done. I am assuming that you want your "My account" page to be in the central area of the store, correct? As a start, you could put each in its own dialog box calling dialog.tpl instead of menu.tpl.