Ok .... I don't have all the answers, but here's my best shot at several of them:
1-2) In civilized lands (which usually follow water sources at first and then fill in the space around and between), you'll have villages spaced roughly at 5 to 15 mile intervals (i.e. within a few hours' walk). These villages are generally tiny farming communities (hence the countryside/farmlands you usually see). Towns and/or cities crop up much less frequently, and not closer than 30 miles or so apart (and that's pretty darn close). How many of those villages, towns, and cities you have will depend greatly upon how many people you have and how densely they're packed into the explored areas of the world/country.
3) It really depends on how old the world is. Land plates (assuming your world has plate tectonics, which I am assuming since you said earthlike) tend to be "lighter" than oceanic plates. So what happens over billions of years is that you start with small amounts of land, but then as the tectonics happen and volcanoes do their thing, the land grows and grows. So 2 landmasses isn't unreasonable, but your world will be very young (and very volcanically active).
4) The answer for this flows from 3 ... since your planet is really young and very volcanically active, it's perfectly reasonable to have archipelagos all over the place. They'll be volcanic (look at hawai'i, the aleutian islands, japan).
5) The short answer is that mountains form when tectonic plates come together, or when they break apart. Random volcanoes happen at hotspots in the earth's mantle (molten layer beneath the solid crust). The long answer is harder to just post up, but this link gives some great demonstrations of the process (and explains what I said in answer 3 about land area continuing to grow over time).
6) This is really only possible while still having a life-sustaining planet if it's localized (look at the weather in Seattle, WA, or there's a city in northern europe somewhere that rains just about every single day, according to the discovery channel). If there's cloud cover everywhere, all the time, it'll throw your planet into a REALLY nasty ice age (not enough light gets through to warm the planet). In fact, this is how they think we ended up with a snowball earth for a while. I suppose if your planet was a lot closer to its sun this might save it from boiling, but my knowledge of those consequences is too limited to speak to. I'd suggest a single localized area of murk instead.
7) Water for rivers comes from 2 places: the sky, or underground. A lot of rivers start in mountains because (a) they get a lot of snow, which then melts and has to go somewhere, and (b) there's a lot of pressure in the ground in mountainous areas (which is what makes the mountains happen in the first place) which forces the water up out of the ground, so you get a lot of springs. But, it rains everywhere and there are springs everywhere. So rivers can start just about anywhere, but often they'll join up with one that started on a mountain someplace.
Hope that helps!
Oh, and I know I sent the link via the pm, but for the sake of those reading because they have similar questions, please check out the resources located here: http://www.cartographersguild.com/sh...ding-Resources and here: http://www.cartographersguild.com/sh...world-building
There's some good stuff in there, and those are just the two most recent threads. A search on "worldbuilding resources" or something similar on the guild forums should yield a plethora of information.