No it will not reset any progress, but if you have any mods that built structures or gave you special items they will not longer be there if the mod is removed.
It will not, you will need to back-up the data manually from FTP, change the map, then if you wish to go back to the old map start the server on said map then upload the data you had saved with FTP.
Extinction is already pre-loaded, once the map is released which will be at 10am PST, you will be able to select it from the drop down list and load the map. If you have any further questions, please let me know