I remember SM did one in a previous version, but has anyone tried with TFH? Thoughts? Strategies? First targets?

You write one book about HOI3, and people expect you to do years of followup research to retain your credentials. Getting tenure will be easier. Sheesh.... :laugh:
Alright, so I tested threat.
Here's what you need to know about Peace in Our Timetm gameplay:
1) All threat generation statistics below assume threat on the UK. Threat against other countries will vary; for those wondering, you generate around 15-20% less threat on the Soviets. I only kept detailed track of the UK.
2) A 4 brigade division of active duty brigades generates 0.08 threat rounded up. (I know it's not exactly 0.08 because doing multiple divisions does not generate neat multiples of 0.08) Type of brigades does not matter in a measurable way.
3) An air wing generates 0.08 threat. Type of wing does not matter in a measurable way.
4) Ships generate 0.08 threat. Type of ship does not matter in a measurable way.
5) Reserves generate a prorated amount of threat. Under Volunteer Army, 4xINF reserve divisions generated 25% of the threat of their active duty counterparts.
6) Almost all of Germany's pre-war decisions (except Spanish Civil War) generate threat AND reduce neutrality in key majors. So, when considering decisions, you can't just count the threat.
7) Without Germany reducing the neutrality of the majors via decisions and increasing threat via military build up, most countries do not have the threat/neutrality ratio to DOW Japan, even if Japan completes Seize the Coast.
8) Putting brigades back in the queue for upgrades generates threat.
9) Upgrading technology via the upgrade slider does not generate threat.
10) Forts, ports, air fields, RADAR, IC, province AA, rocket sites, nuclear reactors, nuclear bombs generated by nuclear bomb-making technology, infrastructure, convoys, escorts, and supplies do not generate threat.
So, with all that in mind, I figure you could probably budget a decent sized German military if you didn't fire any decisions and still not provoke a war. Firing Anschluss and Munich will drastically lower the neutrality of the UK, putting you on the road to war. To grab Austria and the Czechs with provoking a war from the AI, my estimate is that you'd have to keep you non-decision threat well under 20.
I'm not going to test actual applications tonight, because I don't have any booze in the house and it's as boring as watching paint dry. (I ran the previous test at full speed in the background while doing work for hours, but actually building units and monitoring threat requires a wee bit more intervention.)