Many soils come with fertilizers already added.....that's what I mean by fertilizer problems. I grow hydro....not in soil....but do know that many types of soil on the market are too "hot" for seedlings.....ie...there are too ferts already in the soil which can overnute or burn young plants. Unfortunately I do NOT know which soils are the good ones vs the bad ones.....so can't help you with that part.

I hate it when people ask me how to water a plant.....I'm terrible at that kind of thing so will have to leave that for someone else. But I know the roots should not be constantly wet or they will not be receiving enough oxygen and that drainage is probably your biggest key to this.