It is good and important point you have placed in a right place. In your question you have rightly pointed out lot of thing which is multiple angel.
How Much time a day - As minimum as possible.
The amount of time you are utilising is equal to your investment as we are doing business. So Time is here calculated as money.
As you invest more time but you are not getting any result it is treated underutilized.
Be involve and give 100% importance to each area.
Be Positive and remain cool.
Consistency is the key to success of SFI.