Several Questions in Halacha

I don’t know if this belongs here or if it’s more of a learning-type question, but I’ll try:a. I find it difficult to understand why nowadays we wash our hands in the morning with a blessing. According to the Rosh, the reason is cleanliness — but if one sleeps with long clothing, the hands won’t necessarily touch covered parts of the body, so how can one recite the blessing? (As the Mishnah Berurah at the end of Siman 4 writes: in his times people needed to wash because the collar was open, but in our times it isn’t so — so why must we still say the blessing?)b. Why does the Shelah write that one must wear a yarmulke at night? Why isn’t it enough that we sleep on a pillow which covers the head — except according to the Chazon Ish, who requires most of the head to be covered?c. I’m abroad now and wanted to ask: is it permitted to take shelter from the sun under a church? Is it permitted to pass by its entrance if there’s no other option? And to what extent is it forbidden to look at a church (accidentally or intentionally), or at a cross?

Shalom uVracha,

a. We are not dressed in clothing that covers the entire body, but rather in a shirt and pants. Touching the body under the collar, on the legs, or touching the space between the shirt and pants is common, and this requires Netillah.

b. Even if one does not require covering most of the head, the part of the head that rests on the pillow is certainly not considered covered.

c. It is completely forbidden — whether to make use of its shade, to pass through its entrance, or to look at it for enjoyment. Only an unintentional glance is permitted. See sources.

Shulchan Aruch and Mishnah Berurah, Orach Chaim, Siman 4.

Mishnah Berurah, Siman 2, se’if katan 11:
 “And as an act of piety, even for less than four amos, and even while sleeping at night.”

Shulchan Aruch, Yoreh De’ah, Siman 142:
 Se’if 10: “The shade of a house of idol worship, inside it or opposite its entrance — within four amos it is forbidden.”
 Se’if 15: “It is forbidden to listen to musical instruments of idol worship or to gaze at the beauty of idol worship, since one derives pleasure from seeing it. (However, if it is something unintentional, it is permitted.) (This is found in the gloss quoting Rabbi Yeshaya Acharon, zichrono li'vracha; see se’if katan 34).”