What seem to be some of Alexander Pope's main concerns in the epigrams of "An Essay on Criticism"?

An epigram is a short statement similar to making a point in prose, but it is used specifically in verse.

An epigram is a brief, clever, and usually memorable statement.

Although it was Greek in nature, and became its own genre in the Hellenistic period, it is a form adopted by many authors over time to make a point, but in poetic form.

These original epigrams did the same job as a short prose text might have done, but in verse.

Alexander Pope was well know for using epigrams in his verse. Pope make use of this device in "An Essay on Man," and "An Essay on Criticism."

"An Essay on Criticism" is directed not to the reader, but to the would-be critic.

It is written in a type of rhyming verse called heroic couplets.

Not only does this piece provide the budding critic with sound advice as well as criticism, it also provides an insight into the "chief literary ideals of Pope's age."

One epigram notes that often mistakes are singularly made, affecting only the individual, but mistakes take on enormous ramifications when placed in verse.

A Fool might once himself alone expose,
Now One in Verse makes many more in Prose.

This is his first warning, for the epigrams in this piece deal primarily with advice for the would-be critic, along with warnings and pointers. Another epigram notes that it is hard to find genius in poets, but rarer still to find a critic with good taste. Here Pope sets his sights specifically on the critic.

In Poets as true Genius is but rare,
True Taste as seldom is the Critick's Share;

Another example is Pope's advice regarding poets and critics, and who should "judge" and teach others. He states that poets and critics are inspired from the same place: Heaven. Those who would judge, write and teach must prove themselves able by excelling themselves, being good writers. For without the ability to do these things well, one cannot hope to justly or accurately judge the efforts of others.

Both must alike from Heav'n derive their Light,
These born to Judge, as well as those to Write.
Let such teach others who themselves excell,
And censure freely who have written well.