Bumping this thread.
I have not been able to further diagnose my problem but the more I listen to it the more I'm convinced that it is the top engine mount.
I think I will bite the bullet and buy the $200 aftermarket replacement and take it from there. One way or another that mount has leaked out and even if it's not making the noise, it needs to be replaced.

 

OK so i decided that I'll give it a shot and bought the stock engine mount. I didn't want to buy the $200 part just to find out that it isn't it so knowing that the mount is defective anyways i decided to test it with the cheaper stock option.
I changed it yesterday and I'm happy to say that it was it. The car does not make the sound anymore.
At least I'll know that next time the mount fails, I'll buy the after-market one to have a piece of mind. ... or buy another stock one as one aftermarket = three stock ones.