Between Vader quietly walking in front of his men in TESB to get the Falcon and the one showing off his Force skills to kill a few random rebel extras, there is a gap. One is classy Darth Vader, while the other is Darth Jason Voorhees.
I agree. However, crashing a rebellion and capturing his son knowing he is alive and well can happen any day, while getting back the plans of the most important military development of your country when you know that there’s a mole in your ranks that probably has compromised the functionality of the weapon just needs some action to be taken.
I felt that Vader and Tarkin both acted recklessly just because the stakes were very very high, and that is something that explains and changes things in ANH in a better way. Exactly the same way you just do not think of Vader as such a random evil guy when you rewatch Empire knowing all he did was to find Luke.