re: Poker & Is 3betting essential?
To me, online poker is a game of limited information. The more you limit that info the more of an advantage you have on your opponent.
3 betting important? Not as much as setting a raise amount.
Depending on how I feel or think the cards are running for me is how I decide what raise amount I'll use. Also important is what types of opponents do I have. Obviously if there is an overly aggressive player on my table I'll tighten up my range and stay with the 3x. But if I'm sitting with a bunch of nits then I'll lower it to get some calls, you don't want them to always fold to your raise.
Whatever the amount is 2.5x, 3x the thing that is important to me is keeping that raise amount the same for any hand I'm playing. So if I'm running 3x open raise, it'll be that raise no matter if it's 9Ts or AA.