These mods are online compatible. I have them installed in my game for a long time and play normally without error. But don't blame me if you still manage to mess it up, you prolly have to reinstall your game at worst. If you don't want to do so, you can make a copy of your your installation folder C:\Program Files (x86)\Microsoft Games\Age of Empires III before installing. [Exception is the homecity files which are really simple so it's not necessary to worry about backup].
If you have problem with starting the game after installing the Jam Hotkey and UI mod, make a backup then delete the Profile files in Documents\My Games\Age of Empires 3\Users3. You will need to tweak your settings again but the mod will be installed properly and you can start your game normally.
JAM HOTKEY AND UI MOD
by jammainen
Not only the transparent UI looks good but the hotkeys are also wonderful. I can't play without them. Once you try it you will got hooked.
Essential hotkeys are train villager from all town centers, livestock, camera bookmark, all native training are set to Q key...
This mod also includes Building Rotator, so if you already install this you don't have to download the separate Building Rotator Mod below.
DOWNLOAD
BUILDING ROTATOR MOD
by elvarg_Flame
On this screenshot you can see the transparent UI I mentioned above.
The buildings line up nicely with the use of rotator, the only thing you can't rotate is Town Center. It's great to save space and makes beautiful architecture. 21
DOWNLOAD
GAMERANGER|VOOBLY DECKS
by me
It's not a grand mod like the two above but you can get all the basic supremacy and treaty decks in 1 minute. Very usefull if you have fresh installation or lazy to put card one by one.
[Unashamed self promotion]
DOWNLOAD