Just establishing the bases for resupply of coal and docking during storm season was well looked into and accomplished early on.Your post is quite interesting and (having read a large number of your other posts) seems to be informed by a lot of good solid research. However, I question your conclusion that the US Navy did a poor job with the blockade.
The Navy had no preparation for this assignment and was obliged to build up a large fleet to make the blockade effective. That takes time. The naval technology of the time was very primitive compared to what we are used to today, so the initial success of the blocakade runners should be no surprise. Yes, it did take about three years to make the blockade strategically effective, but the US Navy did suceed in doing it, while also doing an admirable job in completing some of its other assignments, such as building a powerful fleet of riverine monitors in support of the Army.