If possible I would like my database to have navigation tabs along the top of each layout, as well as a set of navigation buttons down the side of each layout. However, when I do a "List" layout, the body is only one row high and I can't work out how to get the side buttons to fit around this. Is this possible?

No.

Seriously? I'm not doubting you personally, but this does seem like a crazy limitation.

I don't see it as a crazy limitation, but I've worked with this since v.1 and you've never been able to have a side panel of buttons in list view, so that's my normal.

List views are very useful, especially for reviewing the results of a find. So, I recommend you revisit your i/f design. However, if you want the look of a list view with a side panel, then investigate a self-join cartesian portal. However, portals can't be sorted with a button click, without a fairly sophisticated technique. AND, most importantly, the records shown are always the result of the relationship upon which the portal is based. You could do a filtered portal...

FMP 10 is moving towards having all the navigation at the top of the window, to be more like other applications (both Mac and Windows).

Just work around the limitation. FMP does so much else very easily.