Unless you are very, very experienced at what you do, you won’t have any idea about the decisions that are going to matter, let alone have answers for them. Speculation about how people will use your product is pointless, if not outright dangerous. The only way to find that out is actually getting it out there.
People will tear apart what you thought was the greatest thing ever and be amazed by what you considered was an abomination in the face of established standards or some theory.
It is an humbling and amazing experience.