1. My games so far at suicidal have been based around building up a monster economy as quickly as possible. I now tech trade only at first contact in order to gain parity and a sound economic base, and then seem to be able to easily out-pace them all in research. The Ais seem reluctant to research advanced & master trade - so I always give those to them all for nothing, knowing that they will start sending freighters my way which further improves my economy and also helps keep them friendly. Otherwise, I can't be bothered with the micromanagement of tech whoring.
2. Don't think I've ever built the spin control center and don't bother with any military building at all until the planetary infrastructure is complete (usually around the same time as I reach large scale building on the research tree) . Agree with the points about it being too easy to boost military rating though - I have a psionic weapon large hull with a 48 attack rating for just that purpose. Combined with a few fully developed mining starbases on military resources it doesn't take many of them to be the boss in power.
3. The more intelligent AIs don't always tell you that "They know what you're doing", even when they are aware, sometimes relations just decline steadily and they will declare war with a sneak attack of their own - which is good. It is far too easy to get peace, re-position your forces and re-invade at will though so like the idea of minimum length of treaties - but would also like to see a minimum period before an AI will consider peace if you attacked them. I.e. no more setting up an invasion of one or two poorly defnded planets belonging to a weaker AI, and then getting peace in the same turn so that you don't risk any counter-attacks. Rinse and repeat until AI dead!
My key srategy: Galaxy-wide war is good, as long as you are not involved.

Fan the flames of war at every opportunity (hey, Mr. Drengin, I've got this nice plasma weapon I've just developed - how would you like to test it for me on those Torian cruisers that look dangerously close to your territory?) Keeps everyone else's military rating down, and their starbase spamming under control. Cripples their economy, ergo their research and production. Their only safe trade routes are with you! Always have a few high speed constructors waiting to pounce on resources when starbases get destroyed and you can very quickly control every resource on the map. It is possible to win a military victory without ever being "at war" with anyone, and without ever building or owning a troop transport.