Friz,
The term "bloom" refers to the presence of microscopic algae in the pond called phytoplankton. When the phytoplankton grow fast and persist, it is called blooming- much like flowers bloom. Afterall, we are talking about plants. Blooms are important becasue they are the base of the food chain. Microscopic animals called zooplankton feed on the blooms, which are then fed on by insects and small fish and then on up on the food chain.
Your goals of wanting significant harvest will be difficult if not impossible to achieve without creating blooms by fertilizing or by using artificial feeds. This isn't to say that you can't have a nice pond, but wihout a significant "base", you won't be able to grow fish quickly nor will you be able to create and sustain the total poundage (biomass) of fish in the pond as you could by being more agressive with fertilizing or feeding.
Your fish can still get big, but it will take longer. You can still sustain a fishery, but your overall numbers will likely be low. You can absolutely occassionally remove fish. I would have no problem swimming in your ponds, but the folks here are right that sunfish will nibble at you, especially if you have moles on your skin!! Trust me! I wouldn't expect too many mosquitoes with the presence of just about any fish species.
It's too bad your ponds aren't in an area with more soil fertility, but it is what it is. The important thing is that you are doing your homework now and there are so many people on this forum willing to give their advice/opinions. It sounds to me like you are going to have an enjoyable pond, but just know without any supplemental management (given your soil fertility) that you are not going to be able to have a fish producing factory. Sounds like you will be O.K. with this. Do know that you can change this scenario with a fertilization/and or feeding program. Things will just be slow otherwise.
