Hello Cmdr Delnelrimnim,
Deep breathe!
It is frustrating but the loss of the ship has a serious consequence. So as a tactic best not lose it. Just some points from your post below. Whenever you get the blood lust and bite off more than you can chew use the 2 hours of trading grind to double check your decision making!
Your mention of beam turrets on your opponent suggests an NPC not a player. I could be wrong though, a lot of the advise - particularly the running is true for players as well.
What ship were you flying?
You noticed that the opponent was flying an Asp Scout and determined his offensive threat, excellent! I think you have missed one important fact. Us old timers had to train ourselves in the info was not available in Gamma and I think early release builds. Key question when evaluating the opposition, player or NPC - what is their Elite Ranking? An Elite Asp Scout is going to walk over a turret armed Viper, Cobra or Asp geared up for Trading. The ranking on NPCs determines how clever (something debated at the moment - but we know the high end ones are going to get even better), and crucally how good their components are. Always look at their ranking (under the NPC name and ship on the right of the HUD), when evaluating the fight/flight decision. You'll have different triggers in different ships and of course based on mission timers.
The nice thing about running is surviving is the win condition - it fits with my "do not lose the ship" tactic.
An all turret load out is actually not that hot - not bad for running away though - keeps power management honest even with the NPCs. Consider having a couple of gimbles and the lower weapons as turrets, you'll kill things faster and still get the benefits of the turrets when running. If your on a small ship - well, practise with fixed really makes the difference in damage on the small ships.
When determining whether to fight always remember not all weapons are good against all opponents.
Small hardpoint (class 1) weapons take a penalty against medium ships and a big penalty against large ships. So an Asp Scout uses 2 width landing bay, so is a medium ship. Any turreted small turrets are going to be ineffectual even if they hit (small size and damage is already on 2 levels of penalties because turreted not fixed). As you scale up to Asp Explorer and bigger, you have to make the same decisions with your class 2!
If you choose to fight - always have a plan B. Best way to have a plan b:
On arrival at your target system, use the route planner (not the targetter) to select a destination. If your in an Asp or something with good range (22+ and fuel for 4 jumps), choose a destination 2 jumps away - this way if a player tries to follow your high wake you have used the distance and fuel tank advantages of the ship to avoid them and win the encounter. Make sure you have next hop in route mapped, it is not mapped by default, I use "g" key!
If you do the above and see the tide of battle turning against you simply press the g key and engage your FSD. This is high wake, no mass lock, at the last minute rotate towards your destination - whilst charging FSD pop heat sinks and chaff.
A note on heat sinks and chaff. Chaf "disrupts" lock-on - typically an NPC ignores chaff under 1KM (give or take), so be weary with fast nimble ships such as Vipers. Heat Sinks make a lock on harder to obtain and keep. So when running use both and boost to 1.5KM, sacrifice pips to shields (and weapons) to achieve this. Always know the point in engines when you can boost again.
Always have a plan B when engaging in combat - even when being the aggressor - and remember the 2 hour grind, and how much you want to avoid it! Running is cheaper than the insurance screen.
Hope this helps
Simon