Maybe theymos didn't send any guideline to you but he did send at least a very short one to Blazed and, hopefully, other DT1 members. His instance is very clear:

If you mean that as the only parameter to add someone to DT2 then that would be the worst idea! But that could be a good start as long as you check feedback left by every of those users to see if that trust helps the community and is left with proper arguments, references and without abuse. Or you can check the Marketplace and find users who leave trust there. Those seem better ways to start than those you've dealt with or have exchanged trust with. Of course those are just ways to start, proper checking of their left trust is required

Good suggestion. I've updated OP

Being on DT2 shouldn't mean that user can be trusted with money. It should mean their feedback can be trusted. It should mean the trust they leave helps others see who can be trusted with money.
Those added to DT2 should help the forum by leaving accurate and helpful trust, not just by making good deals
Of course you won't add a scammer to DT2 under any circumstances as he will abuse his power but just being trusted to hold money is not reason enough. Just leave positive trust in that case

Don't take this as an attack. You seem to forget I said this after you actively began to re-check your list:
I have updated the title of OP so hopefully you and other DT1 members don't take it as a personal attack

Sure, random  Coincidentally that metric tells the exact change each one made to their own trust by setting their own list. The difference shown there is the exact effect each DT1 had on their own trust by being DT1 and adding others to DT2. But I was just lucky because the metric was chosen at random

Absolutely, as I've said before. As long as the reason to add those users to DT2 is because the trust they left helps the community, not just because you've dealt with them or even because they can be trusted with money (in that case leave positive trust to them, don't add them to DT2)