Do 1 or 2 kills really make a difference?
The difference it makes depends on your level of play. The higher the skill level of the player, the more they can press an advantage that they get. But it's not something that I would worry about right now.
Like in your example, the person with the blasting wand would have an advantage. However, the difference between 
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is only 20AP. Between AP Ratios, natural Magic Resist, etc. the difference may be only less than 10 damage per ability, a difference that can be made up pretty easily. Like I said, not something to be really worried about when starting out.
Do I really have to follow the meta?
No, not at all. Regardless of what certain people (*with very poor reasoning) might say, the meaning of meta is: what is meta is what is popular. You don't have to play the Flavor of the Month, and I have no doubt that you would, in fact, play better focusing on improving at the champions you want to play rather than being on of those who just pick up champ they have little experience with because "they are supposed to be Meta right now". Same for items; even something as straight forward as what to build first on this ADC has different answers depending on the region.
The biggest thing is being able to justify the pick which, with your example of "Soraka jungle is not the best idea", is something you already know.
Should I go to prom?
I don't know.
All I can say is something I've thought about for myself, is to be open to opportunities. A person has the choice to take the opportunity, to walk through that door, or to miss out on it and that door will be closed. An option, What you can do is: go to prom without any expectations for it, be open to have fun, and hey, if it turns out that it's lame, you can leave early. Just an idea, take it or leave it.
Veigar's nerfs seemed to cause a lot of ruckus. How much was he loved?
The funny thing is...he wasn't.
He seemed to be actually rather unpopular, to my understanding. There are the people who loved him, of course, but his unpopularity is what made that first crippling nerf so unexpected and seemingly made without reason. There was also a rumor that the reason it happened was that he was starting to gain popularity in Korea for his ability to shut-down Flash-plays, which probably didn't help the reception.
A large reason for the outcry about him was the purpose his E served. It was a circular, skill-shot, that immediately planted the cage after its .5 second cast time; a Veigar would try to land the edge of the cage on his opponent to stun and if he missed the opponent or if they dodged, the enemy would be either be in or outside the cage and be able to retaliate. Further, Veigar's W was designed to work with the E; it's so slow to hit that the opponent has to be stunned for it to hit or he would miss a third of his damage. Veigar is a squishy, immobile mage and the E served as both a vital part of an offensive combo as well as his only defense, especially against the popular assassins, with a long cooldown leaving him very vulnerable. Aiming to hit the assassin who has lept on you with the edge is almost his only hope of survival, so the hit to it's reliability was heavily protested. And on top of that, his only reliable damage, Q, was made into a skill-shot, nerfing its net damage to champions.
Veigar, who was fine and going mostly unnoticed, having these changes that seemed to pay no attention to how his kit functioned and after he was said to be buffed for the removal of the Deathfire Grasp is what made the nerfs so shocking to the community.
Edit: Holy wall-of-text Batman! Wow, I did not notice my rambling.
, but something such as Katarina (somewhat) or Rek'sai top doesn't seem so bad. Then again, I'm a scrub a dub, so what do I know? 
A 
and its GG because all they have to do is buy one armor item+runes and you cannot touch them.
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). If you get one kill ahead you can usually decimate the lane.