Basically, but missing one important piece. Arguably the four most important episodes of Twin Peaks are the Pilot (episode 0), Episode 2, Episode 14, & Episode 29.
The Pilot set in up, despite no supernatural elements there was nothing else like Twin Peaks on TV at the time and it caught a lot of people off-guard and intrigued, though it certainly helped back then there wasn't too many channels and so Twin Peaks by virtue got a lot of exposure.
Episode 2 (actually 3, but since we're working with the Pilot is zero thing) is basically what set Twin Peaks to be remembered for years to come on a pop culture and not just historical level. It's Episode 3 where the first real singe of surrealistic bizarre imagery of Twin Peaks creeps up in full force, being topped with Cooper's dream sequence and out first look at the Man From Another Place and the Waiting Room. This episode not only had that defining scene, it also had a number of scenes that are maybe some of the most memorable in the whole series, including the rock throwing scene. This episode basically affirmed for people that Twin Peaks was 'weird' but in a very intriguing way, and the show was much stranger than people even thought from the first two episodes and even further away from the television set-up of the time.
Episode 14 is both one of the most important episodes for a good and bad reason. It's the episode that Laura's killer is revealed in (though Leland sticks around for a couple more episodes after this), it features the scene of Maddy's death at Leland's hands, the reveal, and a number of other memorable scenes. This episode has a lot of good stuff in it, but also signifies the beginning of the end for the show as a lot of viewership drop off after this episode.
Episode 29 is important as the Season 2 finale and the series finale for 20-something years. However it's helped that the episode is what sealed Twin Peaks as an all time favorite series for many, it's the most bizarre the original series arguably ever got and we get our extended look at the Waiting Room and Cooper succumbing to his doppelganger and the cliffhanger ending. This episode stayed in fans consciousness for years and I think it ending on that note elevated the show for many. Like if it ended on, say the Miss Twin Peaks pageant and Episode 29 never happened I don't think the show would've quite had the same legacy as it did, it'd be still somewhat relevant but I think the series ending on such a high note and never properly concluded gave it some additional power.
What I think are the four most important episodes of the original run. For the record, we won't really be able to judge Season 3 in the same way for many years probably as all of these conclusions come after the show finished, grew with new audiences and formed a legacy, and given many years for the show to sort of solidify its place.