Yes you are right. Earlier when I deactivated Alidropship chrome extension and see currency switcher working fine, I did not care about it anymore, after all it is what visitors see that really matter.
Including your first question, it's been discussed in the forum so many times. If you change from the original plugin to the woo version or vice versa, you will start from scratch.
That simply mean the original Alidropship plugin is not compatible with woocommerce plugin, you need to delete the original Alidropship plugin and replace with Alidropship woo.
If you see your first post in this thread, it is very clear what I mean. As you know Social Rabbit is not posting in Facebook anymore. There is no change.
This built in currency switcher is strange. Before the latest plugin and chrome extension update, I cannot change currency when the extension is active. I did not take it seriously since visitors don't have this extension. But this time it is working fine.
The Social Rabbit Skype support is not online anymore. Social Rabbit is posting in Instagram and Twitter now but not the featured product images. Instead it always post the second image of the gallery. It is still not posting in Pinterest, it's been two weeks now.
Definitely the companies will get something, but not all companies announce what they get. If you think every time what companies get, you will have a lot to think about. If they give commission, that's it, there should be some arrangements behind.
If you read about AliExpress Admittad and about publisher, that is what you mean add advertisement. But as I said earlier that is if you signup for Publisher account. But AliExpress EPN is different. It don't have about Publisher.
Manually or automatically if you have registered with Admitad or EPN programs and have a cashback URL, enter it in the cashback URL field in Alidropship plugin you will have a cashback. See more, it is a straight forward guide: http://help.alidropship.com/settings/other-settings/aliexpress-cashback