1)Wait till you see a colony has at least 5% of your culture and some of them are bureaucrats. 0,01% is enough. 0% isn't. Then use the bureaucrat NF and wait. If the colony population is several hundred thousand it may take decades of NF.
If your population is small, or your capital is in the Americas, or you acquire them after 1870, most colonies outside the Americas will never be in a position to be turned into states.
2) You can do it either way if you are prepared to take the time to exploit the way the dumb AI uses its influence, or if you are prepared to take the time to exploit the way the dumb AI uses its troops. Just setting your influence sliders and leaving them isn't going to work unless you have a massive advantage over the AI but if you keep juggling them according to how the AI responds you can lever virtually anything out of any AI's sphere. The basic tactics are to get it to use its influence on other AIs, and get it to use influence on discredits. The big weakness of the AI is that it will never spend influence on you unless you are actively influencing. Grabbing the last country out of an AI's sphere is difficult, but as long as you can keep switching threats between targets the AI cares about, its fairly easy to run rings round it.