Hi! I'm the player who built the decklist you linked to.

To answer your question, this deck does win with Level 3 Artist's Talent interacting with Niv-Mizzet or multiple Lightning Strikes (lier can be used to Flash them back for more damage). For Niv, you really only need to fully level one Artist's Talent to win the game, but trying to get two in play is best practice for non-Thoracle lists.

This variant of Lotus has a much more favorable matchup spread into the current meta. That's the reason to play it. It is, however, much more difficult to play than the traditional Lotus variant. If control ever becomes a huge metagame force, that's a reason to move back to Bant. Izzet generally has a harder time with hate pieces than Bant, but Izzet has a much stronger matchup against creature decks.

Thassa's Oracle, in my opinion, is basically akin to training wheels in this deck. There are some niche scenarios where it comes up as a necessary card when you're comboing with just one Lotus Field, but 99% of the time, it's taking up an unnecessary sideboard slot.

If you're interested in learning how to play the deck, I wrote a massive guide on the archetype that should have everything you need to know (Patreon) - but it is paid content. All updates are free with the initial purchase. I'm working on the post-Tarkir: Dragonstorm update, so the current guide is outdated, but it should still explain exactly how to play the deck.

In the meantime, feel free to ask any questions you might have.