Ok, here goes, when you approach a site at night, leave your lights off, the scavengers will always be using the flashlights and they can be seen quite easily. They often are a little ways away from the wreckage, so look around the site. After assessing the site, turn your lights on if you want and move off, try to land at least 500 meters away, if there are scavengers, they won't go that far from the wreck usually and they can destroy your ship with regular weapons.
As far as automated landing, one of the docking computers does have that, I can't remember which one or how to activate that as I don't use them.
I prefer to always use an SRV as it is your mobile rearm and supply center. Always park the SRV looking away from the settlement/site with a clear path in case you need to escape quickly. No big boulders or other things that would slow you down or cause you to spinout.
If no scavengers are at the site, always keep your ears open, they might drop in on you. At the first sound of another ship, run to the SRV and drive about 250m away and then assess the situation.
When dealing with Scavengers at a crash site from an SRV, roll up to bout 100 meters away and shoot one, backing slowly away. Put full power to the weapons and the rest into the shields. The scavengers will attempt to swarm you, keep backing away and firing, always target lock the one you are shooting at. If your shields drop, you need to move off until they stop shooting at you and let the shields recharge. You can also repair the SRV from the right panel using synthesizing button. Keep doing this until you have killed them all.
On foot is different. Having Level 3 armor and weapons makes the job much easier, but not essential. When you hear the ship drop, sprint away and then sneak back in and shoot one, any of them in sight of you will try and swarm you, keep covered and back away until they stop. Move back in and pick them off one at a time. If you are going to do it on foot, use the dominator suit or a high-level maverick. Run away when your shields drop.
Now to the video, you landed too close and when under attack, you didn't dismiss the ship. When you dismiss the ship, it goes to a safe place, and you can recall it when you are done. You usually don't need to do this unless you are too close.
Driving the SRV from the turret takes a bit of practice, when running over NPCs it's much easier to do from the driver's seat.
You can target from the front seat and fight that way, but you have a fairly narrow fire cone that the gimbal can track. I didn't notice that you targeted any of the NPCs, do you know how to do that?
Also, the video playback was choppy, is that the video or are seeing that when you are playing. If so, you might want to work on getting smother frame rates by adjusting the graphics settings. Smooth framerates are essential to doing combat.