B - May I suggest you read through a post about container soils? It will explain why a highly aerated soil based on pine bark is easier to grow in and offers superior opportunity for plants to grow as near their genetic potential as possible, within the limiting effects of other cultural factors.

Bark is generally less acidic than peat, and both bark & peat-based soils are commonly amended with dolomitic (garden) lime to both adjust pH and as a Ca/Mg source.

If you have any additional questions, you can ask there or here. Someone familiar with using bark-based soils will help you.

Al