Thanksgiving Open Analysis Day 1 | New Openings Against Kids

This was my first OTB event since February, and hopefully the first Canadian event in a year that I could be relatively happy with my performance. A usual feature of events in the Toronto area nowadays for me is being one of - if not the oldest - participants in the top 'Open' section, as the overwhelming majority of my opponents are juniors that are underrated and have way more opening knowledge than I ever have.
Part of trying to reevaluate my chess play has been reworking everything from the ground up to develop a better positional, logical flow to my games - starting from the opening. For this tournament, I had the opportunity to play some openings I've studied for the Black pieces, and can now reflect on some of the decisions I made in those games.

Round 1

Going into the event, I was seeded 3rd of 32 players, which for a successful tournament means I sort-of need to plan on winning at least the first couple rounds. However, there are no true easy opponents in these events - as mentioned above, most of these juniors probably already have more online/OTB experience than me :) and I'm also not that great either. My first game was a Slav against a 1930 FIDE - for context, I am currently at around 2250.

The key in this game was properly evaluating variations - I think I made the right choice, given the context, to play for a more complicated position but risked a worse position due to miscalculations (a stronger player would've almost certainly punished the mistake). All in all, a typical first-round game for me where I remember how the pieces move.

Round 2

North American events typically have 2, sometimes even 3 rounds in a day; the fatigue isn't immediately noticeable, but it definitely grows on you by the 2nd day of these weekend tournaments. My 2nd game of the day was with White against a player (2070 FIDE) that I had a pretty embarrassing blunder & loss against last December, but I haven't studied anything new White openings & could only hope to get to the middlegame quickly and play an interesting game.

This game honestly wasn't any better than the first, and the only common theme so far is pretty lazy calculation by me - reaching a position I evaluate as 'looks good' and failing to properly consider my opponent's options. It should be pretty obvious that a stronger player (one that I am aspiring to be, apparently) would be able to correctly evaluate the available variations for both sides and punish my decisions.

Instead, after 2 rounds I am on 2/2 in a group of just 3 leading players, including myself - meaning that future games would have to be higher quality to continue winning.