Usually a Pro Tour teaches us a bit more about a Limited format. However, given that Dominaria has been around for quite some time, this one didn't provide all that much insight.
One thing that this Pro Tour demonstrated for this Limited format is how amazing it is. Some teams avoided white like it was the plague, while others enjoyed the strategy of white two-drop-based aggressive strategies. Some teams had Saprolings as the best archetype, while others had Wizards. And Sam Black played a deck with three copies of Navigator's Compass, even though a variety of players deemed the card unplayable. The sheer quantity of approaches you can take to Dominaria Limited may be unparalleled, so let's see where this draft takes us!
Pack 1, Pick 1
This pack has some very good options to start off the draft. First and foremost, I think Shivan Fire is better than Squee, the Immortal. While Squee can be a nuisance, it's not all that great. It's not too far behind Shivan Fire, but I would rather take an efficient removal spell over the card.
I can see logic for either card here, but I'm on Shivan Fire. There aren't all that many five-toughness cards, so the kicked mode of Shivan Fire isn't much worse than Eviscerate. I think the option of being Shock puts Shivan Fire ahead, as it's one of the few answers to an early Llanowar Elves or other aggressive starts.
This means the real decision is between Sporecrown Thallid and Shivan Fire. I think this pick is quite close, but I would rather start off my draft with the card with the higher ceiling. While Sporecrown Thallid isn't great in every deck, it's rarely embarrassing and sometimes it's a must-kill-threat. And starting off the draft with the card means I can prioritize the cards that make it potent such as Yavimaya Sapherd.
Pack 1, Pick 2
The Picks So Far:
Wow, this pack has a wide array of options, so let's eliminate some of them to make the decision easier.
Between Time of Ice and Blink of an Eye, I believe I would go with Time of Ice, but I do think this pick is close. In U/B Control decks that look to loop Sagas and tempo-oriented blue decks such as U/W Flyers and U/R Wizards (the more aggressive version), Time of Ice can be one of your best cards. However, there are blue decks that don't care for the card all that much, while every single blue deck is happy to run pretty much any amount of copies of Blink of an Eye. This early in the draft, per the logic expressed in the previous pick, I like taking cards I can maximize, which is why I'm leaning towards Time of Ice.
Between Grow from the Ashes and Yavimaya Sapherd, I think it would be a clear Sapherd. It's one of the best curves with our first pick, and given the lack of quality three-drop creatures in this format, it's just a great card for your curve. I consider Grow from the Ashes quite overrated. While it lets you splash around and do powerful things, I'm afraid to play a deck that has too much air, as you become prone to flooding.
Thallid Omnivore and Shanna, Sisay's Legacy are similar cards to consider pairing with Sporecrown Thallid. While I think Shanna is both less replaceable and more powerful than Thallid Omnivore, I think the B/G archetype is better than the W/G archetype. Overall, I think this pick comes down to preferences, and I would probably lean towards Shanna this early in the draft because I have also found it a reasonable splash in the Saproling deck.
The pick has narrowed down to Yavimaya Sapherd, Time of Ice, and Shanna. The safe pick is Yavimaya Sapherd, but my preference for blue decks in this format is my reason for taking Time of Ice. I think taking either Shanna or Yavimaya Sapherd is acting a bit too married to your first pick. Time of Ice is the most powerful card in this pack, and it's also in the best color. Early in the draft, it's good to stay open and just take the best card, which is what I'm going to do here.