Need info

My 1999 Dodge Intrepid with 144000mi is having a few problems and I was wondering if it may be easy to fix? The door locks seem to have a mind of their own because when we park and get out if we're not careful to make sure it's unlocked, it locks us out and even the key can't open it back up. Correcting it through the dealership is quite expensive so, can I do something to disconnect it so it can't lock us out anymore?
Also, the oil light also appears to not be working right, one day it just started lightly flashing on and off while bringing the car to a stop and when I checked the oil level soon there after, it was totally out of oil! When we opened the compartment to add more oil, it was smoking a bit from there. Is this a simple thing to fix?
Thanks, Kayla