Hi,
No, if you read the message that you pasted from Google, it says that the price will be taken from the microdata.
So Google Products will still need your feed for all the rest of the data of your products.
So you should not deactivate the plugin.
Also, your screenshot doesn't have any error. On the top right of the screenshot, you can see that it says "0 errors".
So it should work just fine.
It just tells you that there is a tag attribute it doesn't recognize, but that's not a problem. The attribute keywords will just be ignored.