There are a number of ways to make your games quicker.
(1) I always use a single governor for all my normal social building. It's not always optimal, but it's good enough and it means that no matter how many planets you have, the game proceeds at the same rate.
(2) I stay out of wars by bribing the AI. Fighting defensive wars is slow.
(3) I keep military spending at zero most of the time. Handling ships is slow.
(4) I don't build starbases for things like construction bonuses and trade bonuses. Building starbases is slow.
(5) I mainly do alliance victories now, but if going for a conquest victory I would either (a) buy up all the influence resource starbases in the galaxy, maximise them, colonise all PQ 10+ stars in the AI's area, and culture flip all their worlds, (b) send out constructors to strategic locations in the galaxy using the waypoint system, then group them into fives and terror star every enemy planet simultaneously, or (c) Build fleets of (mainly) anti-matter missiles and combat transports. When I had enough to conquer an AI, I would send them out and conquer him before he could put up a decent response.
I could never have managed to play at Lothmorg's rate - four gigantic conquests a day on average - but I could certainly have managed three in two days.