SJS – the reason they are bad examples is because:
Eiruv – if you have an eiruv you can carry, its not getting around carrying, if you have one (a kosher one not some “telephone wire” eiruv) then carrying is permitted a simple A then B equation.
Shabbos Clock – I dont even see where this is on the same wave- length, were is the logic the same? You are doing no malacha you arent going to become over on a malacha. So what would be the problem?
Selling Chometz – This is the only one that MAY be SLIGHTLY similar in that you are trying to get around something. While I do believe that this is more of a minhag type thing than anything else, personally I am not so comfortable selling chometz, my family does it, so I do it.
And all of these things I could live without.
The main problem with showers is that you are a hairsbreadth of being over a d’oraisa and SO MANY people have NO problem with that! you press down on the towel a little bit too hard and you are over schita, I promise you, you wont die if you dont take a shower for 3 days. And your schar will be infinitesimal.