Oh well, though I couldn't collect 2000 gold and 60 workers per turn, I have adapted a new tactic for dealing with respawn civs during the last few day. So far, it's working really great (especially on Chieftain). Yes, I have actually tested this one out.
Step#1: Capture all their workers and settlers, take their capital and all their cities to wipe them out the first time - I gain at least one extra city here.
Step#2: Of course, they will respawn again the second time. Just simply wait for about 6 turns later then check to see if they have build their second city yet? Since they respawn with an extra settler, it usually take them any where between 5 to 9 turns later for them to setup the second town.
Step#3: Make peace and demand their second town. Of course, they will hand it over (unless it sitting right on a gold mine or something).
Step#4: Since the second city that they just give me is usually about 5 to 7 tiles away, I use it to rush some troops and send them out to destroy that same civ the second time. Previously, I was hopping to destroy them again and again...and eventually colonize the whole map this way - this would help me to speed up territory gain to boost up the score at the early stage.
If they would have repawn infinitely, that would be really nice. Since they usually repawn to a far away and unexplored region, by using this tatic, I could easily get a foothold on any remote island (before the age of navigation) or any remote region of land for that matter.