I have an old point and shoot (20x optical zoom) and a SIM-free phone that has never been used in my name for anything.
Is the modem completely disabled? Does it still show the "SOS" option that allows you to call 911 without a SIM? If so, and if it's ever been turned on in your residence, there's a decent chance the IMEI could be traced back to your house just based on pattern-of-life movement.
No root needed
not sure why you feel analog recording is necessary. just need a camera that isn't part of a phone. any DSLR, MFT, Mirrorless cameras would be just as good.
however, there's something to be said about live streaming so that even if the camera is confiscated the images are already publicly available.