SE: Unable to understand the sentences is TC&SE

Hi
I started the GRE 1 month plan.
I am following the 1st Series “Text Completion and Sentence Equivalence (TC and SE) Session”.
Or should I watch the 2024 version??

I understood the Math Strategy, but am not able to understand the sentence as whole itself to even figure out the “clue” or the “idea”.

For example:

It is _____ that so many portrait paintings hang in arm museums, since the subject matter seems to dictate the status closer to pictures in the family photograph album than to high art.

It took me good time to understand that this means “Shit Art”

However, this is an easy example.
Few from the homework that left me completely blank are:

Political candidates are usually quite _____, yet their campaign advertisements often hide important differences behind smoke screens of smiles and empty slogan.

“yet” is negative, but what is the clue?? “hide” or “empty slogans”??

But the ones that made me write this plea are

Poe’s _____ reviews of contemporary fiction, which often find great merit in otherwise _____ literary gems, must make us, respect his critical judgment in addition to his well-known literary talent.

Here, otherwise is -ve. But which “idea” or “clue” is it contrasting?
Is it contrasting “contemporary”? So it becomes “great merit in otherwise outdated literary gems”?
Or is it contrasting something else?
Either way, how is unappreciated the answer?

And the other question is

Not wishing to appear -------, the junior member of the research group refrained from ------- any criticism of the senior members’ plan for dividing up responsibility for the entire project.

(A) reluctant … evaluating
(B) inquisitive … offering
(C) presumptuous … venturing
(D) censorious … undercutting
(E) moralistic … observing

Here the clue itself is a blank!
Now, assumed at junior member refrained from “offering” any criticism, so that he would not appear “inquisitive” i.e. that he’s asking too many questions.

However, the answer is (C). How is (B) not the answer, and how do surely arrive that (C) is the only correct choice??

Thanks to anyone taking time and for your help.

When you don’t know where to look, focus on what the blank is describing.

Political candidates are usually quite _____

The blank is describing political candidates, not campaign advertisements or anything like that. So another clue in the sentence about political candidates is “important differences”, so that’s what you should focus on.

You wanna find a clue that talks about the same thing the blank is describing.

It’s the opposite of “merit” right? To give something merit means to praise/appreciate it.

I think “offering” is okay, but “inquisitive” isn’t. They are part of the same research group and they are researching, so curiosity isn’t necessarily a negative in this context. The “not wishing to appear” suggests the blank must be something negative.

Hope that helps!