Hi Roger,
Some answers:
1. If you buy AOW3 on Gog you will be able to play PBEM-games. I am playing PBEM-games with a friend who bought it on Gog, while I run the steam-version (I also bought the Gog-version but not all DLC's on Gog).
2. Yes, quite a few people play AOW3-online, both in the normal online-mode and the PBEM.
Considering MODs; I dont think many people play with MODs online. I currently started playing PBEM-games with the following 4 MODs installed (PS. sorry for the steam links
):
1. More Colors for Coat of Arms- http://steamcommunity.com/sharedfiles/filedetails/?id=525871780
2. Triumphant Heroes- http://steamcommunity.com/sharedfiles/filedetails/?id=519469975
3. Extra support units- http://steamcommunity.com/sharedfiles/filedetails/?id=519448872
4. Structure Reward Variety- http://steamcommunity.com/sharedfiles/filedetails/?id=525193598
Works great. There are of course other MODs, but many are WIPs.
FYI: to install the mods for the Gog-version you can directly download it through the following procedure:
1. Go to http://steamworkshopdownloader.com/
2. Fill in the url of the workshop item (the URL can be found in the Share-button on steam-mod-link) and get a direct download (some browsers like Firefox seem to have problems with download - but other browser dont)
3. copy .Taf-file in ....\Documents\My Games\AoW3\UserContent folder.
4. Launch AOW3-game; in game laucher enable the mode in the tab Usercontent (if game launcher is already running, click update in tab Usercontent)
My personal opinion about AOW3: I think it is a great and fun game that vastly improved through patches & DLC's.
grtz, NVC