I am toying with the idea making some port but I have my usual points
of
confusion.

1. What type of reds make good ports? I was going to draw off a
gallon of a new batch of Merlot. Does it make a difference?

2. The Portugese method seems to be to ferment for 3-4 days then hit
it with 77 percent abv brandy. Other instructions say to use high
alcohol tolerant yeast, and coax the sugar level up as well as the
alcohol content. If the desired abv is ~20 percent, why can't one
simply chaptalize a finished red (13 percent) up to the desired RS
level and then hit it with some 190 proof grain alcohol to raise it to
20 percent abv? There must be something else going on in the wine that
I am missing. What would be the effect if I do as described above?

3. Once done (sugar and additional alcohol), should oak be added for
extended aging?