Gravel...not needed. Does the planter have drainage holes?? This isn't the problem, but for future reference, no need for taking up room in the planter that the roots might need! Planter MUST have drainage holes or your gal will not do well. Her roots will not get the air she needs and will slowly rot, killing her off!
IGNORE the MG soil and fert, stay away from it, go with stuff better suited for MJ....for your own peace of mind, my friend!
Watering, sounds like you need a bit of info here...water when needed, not daily. When needed: Let the gal dry out pretty dry, sticking a finger in and not having anything stick when removing is a good indicator. When this dry, pick the gal up and note the weight, this is how a thirsty gal feels! Water thoroughly, slowly so as not to just send the water shooting through the dryish soil, the soil must absorb the water. Water until you have a bit of run-off....not a lot, but a little water coming from the drainage holes tells you she is quenched of thirst! Now, pick the gal up and note the weight...big difference? If not, stick the finger in and see if absorption was complete.
You shouldn't get in the habit of spraying the plant either....just not the best thing for the gal.
Now, LIGHTS.....you MUST have a lot of light or your work will be for naught. Too little light will mean light and airy buds at best....imho, you'll not reach the "too much light" level, so don't worry! The problem with lights is heat, more light means more heat which isn't good for the gal. 70's temps are where it's at, the goal to aim for. CFL's will grow buds, but not well unless you have a TON of them...meaning a lot of heat! Read the lights section for better options....you really owe it to yourself to do this! I'm not a light salesman, I have nothing to gain by telling you this, just want you to succeed, my friend! HPS is best option, but not only....look into what you can do and do it...FAST!
And AC, you're trying to help, I know....