Sentence Correction

Gauging from the discussion in this thread, the following two points are being discussed here:
1: What does "including" modify?
2: What does "which" modifier modify?

So I will address both these here:

"Including" is not your typical comma + verb-ing modifier. It does not modify the preceding clause. It in fact modifies the noun. Now this noun need not necessarily be the closest noun. It can be far away noun as well and not necessarily a part of the preceding noun phrase.

In this sentence "including" modifies "printed instructions". It basically presents example of the instructions.
Offical Questions with similar usage:
1: OG12#120. In this sentence comma + including modifies the noun - personality traits. In this sentence, this noun happens to be placed close to the modifier.

2: GMATPrep Question
1)A study by the Ocean Wildlife Campaign urged states to undertake a number of
remedies to reverse a decline in the shark population, which includes the
establishment of size limits for shark catches, closing state waters for shark fishing
during pupping season, and requiring commercial fishers to have federal shark
permits.
A. which includes the establishment of size limits for shark catches, closing
B. which includes establishing limits to the size of sharks that can be caught, closing
C. which include the establishment of size limits for shark catches, the closing of
D. including establishing size limits for shark catches, closing
E. including the establishing of limits to the size of sharks that are caught, the closing of

Here in the correct choice D "comma + including" modifies the far away noun - remedies.

So keep this exception in mind. comma + including modifies noun and the noun may be placed little far away i.e. the noun may be separated from the modifies by other modifiers.

Now coming to second issue: Which modifiers or other noun modifiers
Yes, the relative pronoun modifiers modify the closest noun. But they may also modify slightly far away noun. However, there are certain restrictions. For example, there should not be any ambiguity in reference. The modifiers that are placed between the modified noun and the relative pronoun modifier should actually modify this noun.

See this post for more details on this and some examples from OG that exemplify such constructions.