Fusion Engines + Fusion Bombs (or nukes if Fusion doesn't fit) + decent computer. That is the answer to both the lizards and the bugs, and we could take both without breaking a sweat just on the strength of the rich worlds in the area plus the reserve pumped from those not in the area. Turtling is not necessary at this point, though I agree that building a minimal suite of bases everywhere is prudent just in case someone does try to sneak attack one of our worlds. Use of the scanners should give us ample warning of war in most cases. I would be sure to leave each of those two races one junk world somewhere and not genocide them, but otherwise we should be thinking about going on the offensive soon
Or in other words, what Maniac said

I'm glad to know I got SOMETHING right, though aparently you thought I was suggesting TURTELING?

Shields + 5 bases + use of F8/F9 = plenty right now. If somone does come after us, we'll have time to pump the planet with bases and warp 4 fighters, which probably saves it. Losing a planet or 2 doesn't affect us much right now either, and we'd have more than plenty of time to go agressive on defense to avoid losing more than 1 or 2. I think all but the backest line or weakest of new worlds should aspire to having 4-6 bases soon.
I don't agree with shifting research away from computers at this time, and I would probably have left excess research in planetology even though we don't really need it. The surest way we can win would be to maintain and extend our production advantage, and we don't really need any better tools of war than we have right now given the current diplomatic situation.
I'd agree because the vast majority of our worlds that are ever going to matter are maxed out to current tech, so I wouldn't slow down of Robotics IV.
Somehow, I don't expect research strat to matter anymore though. We've either got or are about to get all the tech "biggies" of the era I think, excepting stabelizer to go with fusion drives, and we can't get that atm.
About your last paragraph, I think that's pretty much what I said above so I won't go into that. I've used it in the past too, so it's not like I'm anyone to say anything bad about its use. I've just sort of eschewed it lately as overpowered and somewhat illogical, but I don't mind if others use it.
-Maniac (off to see the doctor)