Regarding your opening question whether aperture would affect "crispness" -- given that your moving subject fills less than 5% of the frame, I think focus was the primary issue (I don't see any sharpness in any part of the image).

To be prepared for possible here-then-gone moments, with a dslr I put my settings at about f/8, 1/500 sec and auto ISO. But that is with the understanding that something might be better than nothing. With distant flying birds "coming out of nowhere," it's usually not

Pic below was with a bridge camera at equiv 1200 mm, into my third year of photographing this eagle nest. I learned from experience to focus on the nest rather than try to catch incoming parents, and to use HQ burst mode: fastest possible shutter speed for the conditions, in this case was 1/1000 in good light - meaning no exposure compensation to deal with.

It sounds like you've picked up some great tips. Just be realistic about your camera limits, especially if in challenging light. All the best!

Please don't start off by telling me I don't understand the exposure triangle or know nothing about photography. I am not necessarily looking for a book recommendation, but rather specific thoughts on how you would set your camera for this particular type of shot. If you have examples of similar shots, please feel free to share them along with how you shot it. Thank you in advance for your kind help!!

Once again, I tried to set up a wildlife shoot. I was in "golden hour" on a partly cloudy evening, I had scouted a spot where there are significant chances to catch various birds and some animal life. I placed myself with my back to the sun and the wind to my face.

My equipment: D3400, Nikon AF-S 70-300 4.5-5.6 VR ED G
Camera Settings: Spot meter, single point focus, Manual with auto ISO

A bit more information: As I was waiting, I found some interesting "fauna" and was playing with my aperture and shutter speed (hence ISO). The aperture was set at 13 when I saw the approaching bird, I spun up the shutter speed (maybe not enough), neglected the aperture, and began to focus and shoot....

Attached is a result. 1st is SOOC, second is with some edit. My questions:

1) The bright white bird is blown out. Should Exposure compensation have been
used differently?

2) Would altering the aperture have given me more "crisp" results? or is it just that
the shutter speed was still a tad low?

3) How would you have set your camera to be "ready" for this short moment
that happens fast and then is gone?

4) Is my G.A.S. for a longer lens a symptom or a cure?
.
.