Who are you concerned about smelling your grow,two 600 w lights will create a lot of heat is the floor carpeted how much trouble will it be to black out the room
Stop watering and feeding ,the soil has everything the plants need until you move them into there larger containers ,stick a finger down to the second knuckle, or lift the container it should be light ,I used pro mix we carry it here in Texas it holds the water a long time
Damping off can be caused by fungus in your soil along with excess moisture ,some people prefer starting in smaller containers to have the ease of control of watering before transferring to 5 gal
Looking at the picks ,I want to say that lower leaf damage may have been from roots that stayed too damp my damage showed up all over, the color of your higher leaves are looking good