need a good reply for this post made on my form

Excellent, Joseph.

As you mentioned in your post there are a lot of factors or uncertainties that we need to evaluate to determine what type of foundation is the best option for our project. Remember that every project is a particular situation and not only because of the structure but also for the location of the project because depending on the location of the project we have different soil conditions that we need to explore, to investigate and to understand evaluating its mechanical properties to determine the soil bearing capacity, the expected settlements, where is the resisting strata located, and in knowing this last property we can choose what type of foundation is better for our project, that is, if we need to use a shallow foundation or a deep foundation, and once we have chosen our type of foundation (shallow or deep) we start evaluating the dimensions and the type of structural elements for the foundation. If we have a shallow foundation, we can choose spread footing, as you mentioned in your post, or continuous footings, slab-on-ground, etcetera. And if you have a deep foundation, you can consider using driven piles.