1 the non-use of umlauts is to make it easier for players with any keyboard to search a province name in game. Players with english keyboards have a devil of a time using the ingame "find province" feature because umlauts and other diacriticals are not standard key strokes. By eliminating all diacriticals, we make the map easily searchable for all keyboards, so more user-friendly for those whose keyboards do not support the weird array of dots, squiggles and slashes common in some languages.
2 On Estonia, the decision was to use the common name used in English for the towns in this period. Hence Reval instead of Tallinn, but Parnu is used since that was, in English-language maps I've seen, more often used. Hence the split between the two languages on the estonian names.
(note this is how it also is in the base Victoria map)
3. On Swedish town names, there was a huge discussion about a month ago, and the solution that the Swedes involved was deliniated in post
459. If you feel that further revision is needed, you might want to PM Sleepyhead and Krantz so that a consensus can be made on Sweden, as I'd rather not have to ask Xie to redraw sections of Sweden every three weeks because of new ideas from a poster that others then disagree on.