Re: fast weapons, what's happening is you are seeing weapons with short cooldowns.
Leto missile, heavy laser, mini beam, ion blast small bomb all have pretty short cooldowns. Chain laser, vulcan laser get bonuses to cooldown after each shot.
Many enemies have these "lighter" weapons. If you're in Stealth B, Mantis B Fed cruiser C, for example, most if not all enemies are going to fire before you.
What makes the game winnable is more than dumb luck, it's knowing what to prepare for. 50 scrap is going to be spent differently depending on the ship (level 3 cloak for stealth B, a second shield bubble for others, more engine power for slow ships, etc).
What makes it challenging is you have to be both tough and killy by endgame. Halfway through, you will have to have a way of getting through 2+ shield volleys, mitigate enemy damage consistently, escape "Kobayashi Maru" situations, and plot your course to both maximize events yet not run out of fuel or get stuck in a dead end with the fleet at your tail.