it smells like hell roasting when you cook soil , i built a solar oven box just to roast soil but it smells so nasty it aint worth it
take yer chances with the bugs
weed likes drainage, a 5 gallon pot should be leaking at the bottom after a gallon of water, thats what you want, my 5 ers get watered about every 3 days avg.even wait till the leaves wilt a little is better than overwatering,
drainage seems to be your other issue, the soil needs some perlite...