More ideas on colonization....
Another factor that affects speed of colonization is the number of different colonies a nation's AI is allowed to develop at any one time. This is the size = # line of the colony = { section of the AI. So if a nation has colony = 2, it can at most start construction of colonial claim buildings in 2 colonies simultaneously and move on to the next colony once all provinces within a colony have claim buildings started. Right now, Britain can colonize up to 6 (yes six!) regions simultaneously, with the French allowed 2 and other nations 1. You'd think this would give the British AI an advantage but in reality it has all that empty space in Canada, Australia and New Zealand to claim first, thus if the Dutch, Russian or Ottoman AI have all their primary colonial areas already filled they can move into other areas (Russians in the Congo, Dutch in Somalia, Ottomans in Nigeria and the like). The solution therefore is I think to give the Ottoman, Dutch and Russian AIs more areas in their primary regions of interest to complete colonization first (Russian in Northern Siberia, Dutch in parts of Indonesia, Ottomans should be able to move into Libya with the TRI state either reduced or eliminated (see Ottoman VIP thread for that discussion) to keep them occupied while the English focus on Canada/Antipodes. Also I think the USA should have its colonial holdings in the Midwest & Great Plains trimmed back - esp in the interior of the Dakotas, Minnesota, Wisconsin, Iowa, Nebraska & Kansas as currently the USA can start railroad construction on the plains in the 1830s when in reality it would be 1860s before that could happen (Transcontinental Railroad completed in 1869). Keep the claims in the border areas along Canada and Mexico, but the interior provinces that could not be reached by the British or Mexicans can be left empty for the USA to start the colonization process. This should ensure that the USA doesn't get a jump on Europe in colonization of Africa. I'd also probably cut the British AI colony = # down to 2 or 3 and French down to 1 to slow the rate at which they can complete colonies early on and raise the costs for various claim buildings, adding more resources like paper, fabric, liquor, armaments to the cost to build them (that should keep the French in check early on).