Whats the worst thing a malicious delegate could do? Double sign blocks? not include transactions? Change their clock settings to cause others to miss blocks? Stop producing blocks all together? Are there worse things that I just don't know about?
All of these things are readily apparent on the blockchain, and can be dealt with if / when they come up. Isn't the point of DPOS to set the level of centralization at an acceptable point so that no single delegate can do any real harm?
For these reasons I think your criteria #1 and #2 are way overvalued. In fact I think their only worth is to help us determine if #4 and #5 are met.
My criteria is as follows
#1 Performance.
Do they double sign blocks? Do they miss blocks? Are they including transactions known to be broadcast? Are they including market transactions that weren't broadcast?
#2 Are they running more than one delegate
Even in the short term I am opposed to individuals or groups running multiple delegates. Look what happens when a node running one of these multi delegates goes down. Long term I think it is even more important that we ensure geographical and political distribution of our delegates. To prevent both collusion and coercion.
#3 What is their pay rate and have they proven that they deserve it
At this point running a seed node and a delegate server should take up around 50% of fees. What are you spending your fees on, and how does that benefit me more than them being destroyed? Can you prove it?
4# Reputation.
Both online and in RL. Most important, do they have a history of theft, graft, violence, or collusion with violent organizations? This is not in regards to running a delegate node, I just think its a good idea overall. There is nothing you could do as a single delegate that would lead me to either call the cops, or come to your house. Other than in reference to #2 and #3 above. I don't care who you are.
#5 engagement level.
Are they reading the forum, upgrading on time, and keeping a close eye on their delegate node? This will all show up in results. I only mention it because you didn't
#6 Technical ability
This will also be directly measurable in the results. Incompetent delegates will not last long.
Perhaps I'm in the minority but I think we are over politicizing what should be and in reality is a very simple job. I think politics is a much greater threat to our ability to stay safe and decentralized than a couple of malicious delegates getting in from time to time.