Could adding oil to boil benefit the taste and texture of the pasta?
It's very unlikely that adding oil is improving the taste or texture of the pasta, the amount people added is incidental to the process. Olive oil is mildly acidic, and if your water alkaline that acidity may neutralize it somewhat, however a tablespoon or two of oil in gallons of water is simply not enough to make a noticeable difference

What is likely to make a difference is salt, as seen in this answer:


  The salt adds flavor, but it also helps reduce the gelation of the
  starch in the pasta. The starch in food is the form of microscopic
  grains. When these grains come into contact with water, they will trap
  some of it (think cornstarch in cold water), but when the water is hot
  they swell up like balloons and merge with each other, and you have
  starch gelation.


When you add the salt is immaterial as long as it dissolves in the water before you add the pasta.