Nonsense. The DTV is in a separate category. For a tourist visa, you usually get only 2 years but some offices might grant a 5 year license upon renewal to holders of the METV. Might is the key word. For DTV holders, some offices grant a 5 year license upon renewal, others only 2 years.
I think so. To be safe, apply within 3 months, but technically, for a DTV, there should not be any issue not using it within the first 3 months. Other visa types do require activation within 3 months (except for multiple entry visas that are valid for 12 months or more, which operate the same way as a DTV).