Dear Derrick,
To a first approximation your assessment of the time lag argument must be right. There are dozens of ways of arguing this. In fact if a student of perception puts themself in the position of testing their hypothesis in any practical way whatever they will find themselves compelled to conclude that what we experience is something constructed in the brain from sensory inputs both recent and past. The nature of the construct is always as much dependent on the nature of the sense organs as on the physical influences from outside. 'Directly experiencing the world' turns out to be a pseudodynamic folk concept that cannot be explicated without self-contradiction. 

However, the reason why there may still be debate amongst philosophers about what is done and dusted fact in physiology labs is that the alternative to direct perception that you give in (4)  is also inconsistent with science. What we experience is not a mental simulation of the world. It is an experience determined by physical laws operating both outside and inside the brain. The operation of these laws does not in itself have any appearance (because appearance is always appearance to something). There is no 'stuff' out there that our experience 'simulates'. Such an idea is as self contradictory as the direct perception one and modern physics shows empirically that it is invalid. All we can say is that the world consists of 'what is really going on' and that this is the operation of instances of dynamic physical laws. There is no such thing as a 'veridical' experience, in the sense of being 'truly like the world', simply one that depends on the dynamics of our current environment in a way that we can readily dissociate from influences from e.g. the dynamics of some past event that flavours our interpretation of the present or some inconsistency in the dynamics of our sensory organs. 

Another way of putting it is that the concept of 'representation' is too imbued with intuitive category mistakes that it is best jettisoned. Our experience is not a re-presentation of a world (that has previously been 'presented'). It is not even a presentation, I suspect. It is an actuality determined by the operation of instances of dynamic laws that are real and concrete but unenvisageable as 'stuff in a space'.

Jo E