So it all started a month and a half ago, my Altima began showing me low battery. I got new batteries for the fob. Worked fine for 3 weeks. One day I go to get my haircut (-35c out) I start it with my auto starter (car was plugged in), I take it to my haircut, it sits outside for half an hour not even, I come back and It won't recognize my key. I try a few things with no luck, decide to leave it on on the street and come back tomorrow. I come back the next day, hold the key up to the Start button until the *Push the break* light comes on and It starts. To be sure, I went and got another set of new batteries. After like two weeks I get snowed in, heavy. My dad and I dig my car out and to shovel the rest of the snow under the car I start it (normally from the inside) and move it up a bit to get the rest of the snow, after that I shut it off and head back inside. Next day I jump in my car, try to turn it on and only light that comes on is the Orange Key light so basically it doesn't recognize my key at all.
I tried the method I used last time of holding the key up to the start button without luck.
I tried replacing the keyfob batteries again.
I tried replacing my car battery with a new one.
I tried starting the car (or at least seeing if it will put me through to the *push the break* light) while getting a boost).
I tried unplugging and plugging back in the two cords leading to the break pedals (brown and white I believe).
I tried unplugging the car battery for 15 minutes.
I tried using the spare keyfob (with new batteries).
Car still starts with autostarter because I was told it bypasses the immobilizer - but now even the purple blueish light that used to flash when I locked my car is gone..
Is my immobilizer the issue??

I'm starting to think I should take the panel off and fiddle with the steering lock mechanism since I've read its somehow all connected and seems to be the cause of the problem. Can anyone confirm? also, will this mess with my warranty?

Thanks in advance.