The throttle linkages can look a little strange to newcomers to the style and are quite baffling if popped off and you are trying to figure out the correct orientation- but yours is all good.
The muffler bend- unknown how or why it got in there- could be heated and pushed out from the inside via the exhaust port if you really wanted to- but at the moment is causing no real issue.
The inner deflector is factory and helps deflect hot gasses away from the plastic brake flag- which and and will melt flags in half in a fairly short run time if bucking serious sized logs.
Holes in, incorrectly fitting, top and bottom halves not clipped together, misaligned rubber gasket between air horn and filter base are the main reasons for sawdust entering the carb internals.
Can be from the fuel tank- but usually that involves a missing/damaged fuel filter, or split in the bottom of the fuel line.
Running way rich will not score the piston and cylinder as such, but over fuel everything to the point of the saw not running well- often older saws are found way out of spec in an effort to mask an air leak. Read about four stroking and burble that cleans up in the cut- at 2+ out on the H at full throttle in a non leaking saw should be way past the burble unloaded and not clean up in the cut- over fueling to the point of having a wet oily muffler.
