Times are getting tough for Polygamists...

[Pindar]

Another question: how do Mormons harmonize the existence of their post-Jesus prophets with Bible scriptures that say that there wouldn't be any? (in Revelation, I think- not sure though)

There are no scriptures that say there will be no more prophets. There is this:

"Behold, the days come, saith the Lord GOD, that I will send a famine in the land, not a famine of bread, nor a thirst for water, but of hearing the words of the LORD: And they shall wander from sea to sea, and from the north even to the east, they shall run to and fro to seek the word of the LORD, and shall not find it." -Amos 8 11-12

Which is taken as an Apostasy from the truth.

I think what you are thinking of is this:

"For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book." - Revelation 22:18-19

This is sometimes taken as one reason any additional scripture should be rejected (including any scriptural claims by the Book of Mormon). The Mormon rejoinder would be the book is referring to itself: John's "Apocalypse" and not to any larger canon as at the time of his writing the Bible did not yet exist. Another example would be:

"Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the LORD your God which I command you" -Deuteronomy 4:2

which if taken as precluding any additional scripture would exclude all texts that followed Deuteronomy which is grim news for most of the Bible. The Bible itself would gradually come together over the next few centuries following John as various texts came into or out of favor. The Book of Revelation was one that was in dispute but ultimately made it into the fold.