I did not read Reply #7 before I went back and tried again. I think those are great tips.
I finally beat the mission on Suicidal level.
How I accomplished this was I realized that my main problem every time I played was running out of money. (Without sustainable trade due to dread lord attacks, I found money always short.) So, I allowed the AI to go toe to toe with the dreadlords on Suicidal. First turn, on the second colony, I bought a starpot and a colony ship with move of 5/turn. I bought a similar colony ship on the main colony. This allowed me to beat the AI to 2 planets. Otherwise, they get there first.
I put 66% spending on social and 33% on research early in the game and limited myself to 4 colonies (maintenance too high on too many colonies before taxes kick in.)Then I focused my tech on planetary bombardment tree (soldiering techs) and on economic techs: raise morale and raise tax bonus. I was able to easily trade for research tree and factory construction tree when I was ready to upgrade my planets. I put at least one market-type improvement and one entertainment-type improvement per 6billion people.
I bought a ship if I needed to defend against dread lord transports (autosave every 2 turns makes it easy to reload if necessary.) Also, admittedly, I did save/reload upon conquering a planet until I got some good tech. Once I got beyond mortality... funny, but useless.
Then I was able to find all my buildings at 100% and crank some research.
Then the torians conquered the dreadlords while I was thinking about cranking out ships.

So far, Suicidal on Apocalypse (level 6) is proving hard. But hey, I haven't finished my first try yet. I think 6 colonies is too many. I'm gonna take my own advice and go back to 4.