What are you doing in part 1?
Bringing solver up would be one of a good things there since you can sometimes go afk or 20-30 secnds a portal. so why waste that time just before part 3?
2nd People with spell points shrine, and ... why should anyone else wait for them?
Buffing before part 4... so fire, sonic, fom, poison, Gh maybe, masses. so its like 500 sp?
Do your puzzle and start jumping in water in part 3 since most of teams like healer to stay in center [ not me personally but w/e]
But as Zombie and couple others said only problem with part 3 is when someone wont say they can't solve their puzzle, or if someone just leaves his puzzle behind unsolved [ i just love this ghost rooms]
But waiting 1-2-3-4-5 mins after part 2 so everyone can shrine, do bio and w/e else? No way move your shiny slow poke behinds.