here is my 2 cents
NO to MG soil, No to fertilizer sticks. i grow with MG powder/liquid fert all of the time, and the only time i nuked a plant was 10 years ago...it was my first grow, and it survived. just remember that when it comes to the amount, less is more (as
@JSB99 signature states), but ive also learned how to dial it in correctly. but of course, to each their own as we learn how to grow with the tools available. my fertilizer expenses are very low. as for the quality of my weed; it's strain/pheno dependent for quantity, size and taste. i always cure for min 4-6 weeks so mine are never harsh.
ALWAYS journal your grows, you can learn a ton and were you likely made a mistake.
good luck my friend, and hope things works out for you.