Simple advice that will help anyone reach Super Helldive - Remember to ABC
Always
Be
Checking
Checking what you ask? Everything.
When you slow down to regain stamina spin your camera around you quickly to check your surroundings.
When you are waiting for the Lidar to finally finish going up check your ammo, health, and thowables so you know you're ready for the next fight whenever it comes and if you need to call in supplies during the window of downtime.
When you grab cover in a firefight or get a little breathing room from the bugs chasing you check your minimap quickly to make sure you know which direction to fall back toward and which way you are bring flanked from.
In fact check your minimap all the time, it is such an absurd tool that folks apparently ignore most if not all of the time which likely leads to most of their deaths.
In general be aware of what is happening in the game that can affect you and what you can do to best minimize any chance of dying.
Yes this all sounds obvious, that's because it is. Yet there are constantly posts and comments in all of the subs for this game complaining about "unavoidable scenarios" that are anything but. The minimap provides you with so much information on what you should be expecting around you even if you can't see it yet, and your eyes provide you with the more detailed reality of where the Fusion Cannons on this Fortress are - there is literally no reasons to die to one that could not be avoided.
Game knowledge and situational awareness are more important than being able to aim in this game, especially when explosive primaries take care of that for you.