A womanizer, yeah probably. He was known as someone who sought out the attention of women other than his wife
The other stuff, I don't know. I have no idea what a "trained communist" is, but I don't think it's accurate to refer to him as a "communist", although his politics were generally left-wing, I think it's fair to say. At the time he was very pro-worker and his opposition to the Vietnam War earned him a ton of negative press attention at the time he died. It's funny, if you read some of the last major publications related to King before he died, from publications like Time magazine etc, they often have a very condemnatory tone when discussing King over the issue of Vietnam...I think a lot of people assume that he was worshiped in the media at the time he died but that is definitely not the case
MLK was also the victim of a very shady campaign of character assassination by the United States government (prior to his literal assassination). So that should obviously be taken into account when evaluating some of this stuff