When we get on our knees and pray to the tomb of the unknown soldier and dedicate our lives to the unknown soldier and ask the tomb to give us salvation and grace, is it still veneration to the tomb???
I won't address praying to or asking questions or favors from a tomb, since a tomb is an inanimate object and I suspect a person who did that might possibly be hallucinating. But in the full and formal sense, we should dedicate our lives to God only. Other secondary dedications can "fit in" under that, but none can replace our primary dedication, which is to God.
Get it?