" Matt.24 does use parosia and comming interchangeably-vs.30,36,37,42,44,50."
Yes. Technically speaking - from a strictly linguistic standpoint - there is a difference between presence and coming. However, this techinical difference is mostly irrelevant since the presence starts with christ's coming. This is why the NT writers use the 2 terms interchangeably. Watchtower is making much ado about a technicality that is irrelevant in the context of the NT.
Also, contrary to Watchtower's claims, the events that Jesus mentions in Matthew 24, indicate, not that his presence is here, but that it is near.
"Likewise also YOU, when YOU see all these things, know that he is near at the doors." - Matthew 24:33
Jesus often illustrated/compared his return to that of a person (a master, a bridegroom or a thief) who returns/comes to a house, unexpectedly. His disciples are always pictured as the ones inside the house - as slaves or as virgins of the bridegroom. With this in mind, when is the visitor (Jesus) actually present? Is it not when he enters the house? Obviously so. When he's not in the house with the others he is absent. The expression "near at the doors" used at Matthew 24:33 appears to be an implicit allusion to one of these house visitation comparisons that Jesus often made. If he is near at the doors he is still outside and therefore not yet present - but just about to be. Thus contrary, to what Watchtower claims, Matthew 24 gives events that would indicate that Jesus' presence is near - not already here.