In this passage, scribe 2 of 𝓟 initially wrote “pain and affliction and temptation”, then corrected this sequence of singulars to plurals (each s is inserted inline and with slightly heavier ink flow, perhaps the result of scribe 2 redipping his quill). Either the singular or the plural is possible for these nouns. Consider, in particular, other passages that refer to the suffering of Christ; for these passages, there are instances of both singular and plural for pain(s) and temptation(s):
Generally, the three nouns pain(s), affliction(s), and temptation(s) are not conjoined in the text, neither all together nor in pairs; the only other example besides the one in Alma 7:11 is in Mosiah 3:7, listed above. Overall, the text allows both the singular and plural for these nouns:
singular plural
pain 8 times pains 19 times
affliction 12 times afflictions 79 times
temptation 9 times temptations 10 times
In each case, we will let the earliest textual source determine the number. Here in Alma 7:11, the corrected plural nouns do not appear to be due to conscious editing; instead, they probably represent the reading of the original manuscript. The critical text will accept the plural readings for this passage.
Summary: Accept in Alma 7:11 the corrected plural nouns pains, afflictions, and temptations; the original manuscript, not extant here, probably read in the plural since either singular or plural forms are acceptable.