that's a really big set of questions, one of the kayak fishing specific forums, like NWKA, would be a good source of info but you might get some snarky responses if you ask for too much in one post. You should be able to find existing threads that discuss many of the things you are asking about, especially once you narrow down to some specific brands and models of boats.
my take on the "pedal vs. paddle" question is that it comes down to past experience, physical capabilities/limitation, where you plan to fish and how you will be fishing (trolling, casting, jigging...) and how much you want to spend. I am a pedal kayak guy because it leaves my hands free for fishing/steering/eating and it fits my physical history (decades of back packing, bicycling, and carrying a golf bag all over creation). By using a pedal kayak, I don't need to compromise on any of my fishing or fighting/landing techniques.
Paddle kayaks come in at a lower price point, some people have non-fishing experience with them which makes extending that to fishing a logical step, and some people have physical limitation that restrict their ability to pedal. Also, if your main fishing is going to be casting for bass on lakes and ponds or jigging for bottom fish, a paddle kayak doesn't limit you.
However, ocean salmon is a different situation- this would be trolling with barbless hooks. You can definitely troll in either type of kayak but you can't fight a fish and paddle at the same time. The powerboat folks use the term 'keep it in gear' because keeping salmon on barbless hooks goes better if you keep moving. In a pedal kayak, a popular technique is to keep moving while you fight the salmon from behind, eventually bringing it up alongside the boat and netting it while moving. There just isn't anyway to accomplish this with 2 arms if your only propulsion is a paddle. And if you fight an ocean salmon without moving, it can get the kayak moving towards it when it makes a run and when it stops, the boat is still moving towards it, line goes slack, fish goes away. A nice shiny chinook taught me that lesson just OFF Florence in August 2019.
cheers, roger