Might want a bit more perlite in there for drainage and to prevent some amount of compacting that will occur over 3+ months of watering. Miracle gro? think that has a tendency to burn plants (their slo release soil or the recommended dose on ferts), so just keep eye on it.
Fwiw, a lady i bought from in 1999-ish used mirale gro fertilizer and her buds were fine.
As far as germinating with any method.. rarely will be a different timeline. Any extra handling of seedling or its roots has potential to stall it. As long as that doesn't happen, shouldn't see any different except for what is caused by genetics and environmental variables.