Jimmy,
Some questions for an aspiring M3 owner. I'm a MOD slut as they say, so I'm doing all my research on the MODs right now before I pull the trigger on the purchase.
1. Does the Akra EVO automatically produce a Check Engine Light (CEL) once installed? (that's the assumption I've picked up from reading the forums on Akra EVO's, hence the "Delete-R" references)
Yes the Akra Evo will give you a CEL, if you dont like looking at it you can get the Akra Delete or what I recommend a tune
2. I assume the ESS Tune also provides a way to erase the CEL,... but what happens when you have a legitimate problem and the car needs to warn you with a CEL? Does it never show a CEL since you've erased it?
This is a great question; I would assume that a tune is written to erase specific errors. So the tune is written to erase the error that the exhaust system is sending out which would mean it is not written to erase error's on anything else? I am really not sure about that my friend and you bring up a great point. This might be something you will want to shoot Roman@ESS a PM about bc I don’t know 
3. Just out of curiosity. You mentioned that the tune was easy to install, with just a cord... where in the car did you plug in the ESS Tune (location)?
Yes it was very easy to install. When you buy the tune set up I did Roman sends you a flash drive and a cord that connects into your laptop and your ECU. You take the flash drive which contains the software for the tune and install it onto your laptop. Once you have the software on your PC you then plug the cord into your USB port of your laptop and the other end into your ECU which is located driver side front door right around the hood release button. There is a small plastic panel that just clips off. You then download your cars data onto your PC. The software groups this info into two folders. Once this is complete you mail it to ESS. ESS receives your data and writes the tune for your car and emails it back to you. Once you get the email you take those folders which contain the tune and download them into your car and you’re done. It was really simple for me
4. If you had to bring the car back to BMW for any reason (general maintenance, recall, etc.) and you re-flash your ECU back to stock w/ the ESS Tune, is there "any" way that BMW could find out that the ECU had been remapped or modified at any point? I guess what I'm getting at is the concern for the warranty... [I figure I ask this since you work for BMW ]
There is a way that you can flash it back to stock at anytime. Most dealership if you flash back to stock before you bring the car in they will not knock you however like I always tell everyone MOD AT YOUR OWN RISK 
Any mod can technically void your warranty if it is not OEM.
Otherwise, beautiful M and I hope to actually have the same setup when I finally get mine. The Akra EVO has been something I've been eyeballing for a while!
Yes this is an awesome set up and I am very happy with it as I know you will be also 
I hope this info helps once again I am not an expert on all this stuff all I can do is tell you my personal review on the products 
for any technical question I would recommend you contact the vendor who supplies the product that you are interested in