I should change that face next to my name, it makes my messages seem more aggressive.
To short awnser most of the questions,
it depends (1$ to lyle)
THe main part of the diet should be unprocessed foods. Once a large proportion of these have been eaten, there is still the possibility to have lots of other foods, fats included.
THe base of my diet is around meat, veges and fruit. Then on top of that is whole wheat bread (generally either store brought or homemade-slow fermentation homemade is best!

and a little pasta (not a lot cos the energy is too easy to add up)
But the majority of energy comes from whole fruit and veges. Oats are good, relatively energy dense if uncooked, but not if uncooked.
WHite is ok as long as it doesnt take up the BULK of your diet.
This is normal dietary practice.
Ok. For your question two, see above.
Question three - The RNI's are basically recommended intakes, they are calculated from the upper 5% level on the std curve of the nutreint needs formed from a rather large amount of studies. That way it will cover the needs of ~95% of the population. So if the RDA for calcium is 800mg and you are only getting 500, it doesnt mean that you are deficient in it. Because the needs can be anywhere in that 95%. (while it is possible that you are in the 5%, thats where statistics starts going into play)
Question four - Bodybuilders are nuts. Its taken me a number of years to get to this point but I Think its definately the right one. You must know that X is the defiante thing.
You will never know if you are getting the right amount. If you take a multivit, how do you know that you are not limiting your results due to excess of a certain nutrient?
Im poor as well at the moment, because i work almost full time to support my wife and two kids, whilst studying full time. ITs hard keeping enough fruit and veges going to keep me filled up, i rely on frozen a lot. NZ is relatively cheaper for most things, but also wages are lower to meet that.
Its all hard work, in the perfect world, it would be a lot easier.
Its the main reason for so many convenience foods, and also probbly a lot to do with the current obesity epidemic. Easy access to high energy, low nutrient foods.
Would convenience foods plus multivitamin make up for the lack of fruits and veges, probbly not