Have you tried with new vinyl or old ones? If you have any new ones try them out, it makes a huge difference. If you have older ones like from a relative, they might have been "plowed" with some bad old needles, like ceramic cartridges which used to be more popular in the past and which require much more weight by design.
Also is your brush anti-static? Static electricity can often be the cause of pops.
I think in the end, even with new, clean, static-free vinyl, it'll still have a significantly higher noise floor than a CD/mp3/YouTube/etc...
Edit: no comment regarding the headshell because I'm not familiar with that kind of design but looks fine from the pictures.