[Edi]

1) There are 4 possible slots for sites per each province. First slot is checked against site probability. If site appears, it is randomly determined. Then next slot is checked for site probability. As soon as a site slot comes up as empty, it and all the slots following it will remain empty. So if the first one comes up empty, no sites at all in the province.

Common sites have a greater likelihood to appear than uncommon sites, which again have a greater probability than rare sites. If the random determination results in a rare site, that result is rerolled and the second result will be the actual site that appears. In other words, a rare site appears only if the reroll also comes up as rare.


2) The exact percentages of common/uncommon/rare are not known, but I'd throw an off-the-cuff guesstimate of 60%/30%/10%, give or take something. It'd need some statistical analysis of a fairly large sample size with controlled terrains to get reliable results, and even those would be rough results.

3) The relationship of site icons to their level and rarity is not clearly established, but there seems to be some correlation, in some cases at least. The correlation seems to be more closely to the site level than to rarity.