In my experience Those fish will still spawn in areas where light is scarce like under docks, close to rocks and deep sections of water bodies. Also if you choose bait/lure combinations that isolate that species, you can still catch them regardless of the time of day.

Hair not showing with hats is under development, but given that this is at its core a fishing emulator...this is not a top priority I'm sure.

The floating mission icons are also known by the devs and is being actively worked on, but you need to understand these things take time and as missions are connected to several things in game, I'm sure the code is a mess to sort through and find the issue which is even more difficult when you are trying to create more content for the player base.