Librarian verses Plagerizm and a Recipe

I once had the grand idea of creating a cookbook to raise funds for my school library.  I scoured the internet for copyright rules for recipes and found little help (this was over ten years ago, maybe now there is more information.)  Finally I turned to the food editor of our (somewhat) small-town newspaper.  I can't believe that the food editor comes up with up to half a dozen original recipes each week - she has some really good stuff! (Librarian note - I will have to check out if there is a source for non-copyrighted recipes.)  Anyway, I contacted our local news-food editor regarding recipe copyright law (only a librarian would inquire).  The response was that if you start with someone-else's  recipe you must make 3 major changes to the recipe to make it your own.  And a major change is not changing the amount of salt... (note: this is not a direct quote)

So here is my "original" version of a rice and corn salad adapted from a variety of recipes.  This can be vegan, vegetarian, or neither!

Colorful Rice and Corn Salad
Serves 8 as a light supper (or more as a side dish)
Takes about 45 minutes to prepare (using some precooked ingredients as noted)

Ingredients:
2 cups pre-cooked long-grain rice
1/4 cup lemon juice
3 TBSP olive oil
salt and pepper
1 TBSP cooking oil
1 small package (10 ounces) frozen corn, thawed
1 fresh poblano chile, chopped into 1/4 inch dice
1 red bell pepper, diced into 1/4 inch dice
2 small zucchini , diced into 1/2 inch cubes
1 cup grape or cherry tomatoes, sliced in half
1 cup semi-ripe mango, diced into 1/4 pieces (note: I use packaged, fresh cut mango that does not look super fresh and moist - you want a bit of crispness in the mango and not have it be super sweet but you can slice and dice an almost ripe mango)
1 bunch sliced green onions
1/2 to 1 cup (to taste) chopped fresh cilantro

For more protein add:
1 to 2 cups diced (1/2 inch) Colby cheese
and/or 1 to 2 cups diced pre-cooked pork or chicken
Note:  if you add both cheese and meat, use 1 cup each.

Instructions:
Whisk lemon juice and olive oil with salt and pepper (to taste) and set aside.

Heat the cooking oil in a large nonstick skillet until it just starts to smoke.  Add the corn, diced poblano, red pepper, and zucchini.  Saute until the veggies are slightly toasted.  Scrape veggies into a large bowl,  add all the other ingredients and the dressing and toss to coat.  Season with salt and pepper.  Serve at room temperature.