Emissions have a longer warranty due to federal guidelines so you should be able to warranty those items if they require replacing as per TSB or anything else under the warranty program.

As for the christmas tree lights engaging, sometimes a simple cel can cause the others to light up. the easiest way to diagnose what the root of the cause is by visiting your local Autozone or any other auto part store and rent (for free) a CEL code reader and check for yourself. Sometimes you'll do it for you but for the most part it's easy to do.

Once you get the codes you'll have a better idea what issues your vehicle is experiencing so this will be a good starting point.

Also, these code readers can also clear the codes (the only way to clear the xmas tree lights). Disconnecting your battery does not reset your codes (older vehicles with OBDI can but not OBDII vehicles).

Good luck