Wards

You bet. Its super important

Nope.

Better to save up for gold-efficient items so you can nuke your enemies. Why ward to keep track of their position, when you can just kill them and be 100% certain that they aren't on the map at all?

if your team builds their core items and doesn't buy wards, you can win the game, if your team buys wards only without the core items you will lose inevitably. therefore wards aren't that important

Not really. Having a good number of hours spent in the game will give you the experience , knowledge, and trends of the path people take at certain stages of the game. Over extending mean your getting ganked. Keeping a glance of the mini map and putting the together pings.Will give the information you need to guess extremely accurate in where the enemy jungle is at. Say the jungle ganked top and you're playing adc that mean you can over extend . say jungler ganked top and mid is missing . mean both top and bot need to stay alert and not over extend. You get good at reading information eventually wards become some what needless early item. Lets face it after laning phase is over and if your losing they're either going baron or drag. the decision then become do we have enough damage to even contest it. IF your winning well hell do you need baron, dragon or push in base. Why would you even bother going in the jungle on your own after that laning phase anyways.

Thanks guys, your comments were really helpful. I've been playing a lot lately, and even though I don't find wards to be essential, I feel that they are a great help.