Regarding the OP:
Walking in front of one who is davening
R’ Shlomo Zalman was famous for saying there are cases where this is Muttar (e.g. someone is blocing an aisle)
Raising hands/ eyes to the ceiling by davening, making faces
Raising hands or eyes isn’t wrong per se. It’s just pointless. But if it helps with Kavanah, there’s no reason not to do it.
Eating less than the required amount of bread/ matza by a Shabbos or Pesach seuda.
It is really hard to have less than the B’dieved Shiurim. According to many, even the Lechatchilah Shiurim are pretty tiny.
Davening with the eyes open, looking around
The Kabbalistic Seforim (some quoted in the MB) have very bad things to say about this, but some contemporary Seforim have Heterim/Limmudei Zechus (I think I saw a strong one B’sheim R’ Nissim Karelitz).
Not washing mayim achronim properly
It is a Machlokes Achronim on how to wash Mayim Achronim. It is nearly impossible to not do it properly according to some Shittos. (Of course, it’s impossible to do it improperly according to those who hold it’s not necessary at all.)
Not learning enough Torah on Shabbos & yom tov
What is different than any other day?
Also, this list seems weird. Some of them might be problems in many sections of the Frum world, but some of these just aren’t. Why didn’t you just list the whole Mishnah Berurah and be done with it?