Thanks for the race report and congrats on your experience. Wow, you had epic conditions.
I did the Norseman in 2014 and have wanted to race the Swissman ever since. Did you hear how many people entered the lottery, in 2016, from outside Switzerland?

 
Did you use trail runners or regular running shoes? Thoughts or recommendations?

Regular shoes are absolutely fine.

(SM 2014)

Any advice on gearing? I'm right around 5 hrs on a 'typical' IMNA course, but also a tall and therefore heavy guy. I'm thinking a 39 x 30 will be plenty. Foolish or just fine?

I had 36 x 28. Was ok - but i wouldnt have said no to one more gear! The hills are not that steep (mostly 6-8%) - but:

1) the cobbles in tremola slow you (at least me!) down, which brings your cadence down.

2) you Will be climbing for a looong time - and the Descents are Quick so not that much time for restitusjon.

Youll probably manage 39x30 - but an Even lighter gear could be more comfy, especially ir you dont really like cadence below 60

Yea - I would not choose trail shoes for this run - run shoes would be better imo :)

Pretty much this. It's not 'rolling' it's 3 big climbs, they are long.
So if you don't have any experience of alpine length climbs you might want to factor this in.
In addition they are pretty high altitude (for Europe) and this will sap your power capacity.