"Loughner drank heavily, to the point of poisoning himself"
"Loughner drank heavily to the point of poisoning himself"
However, in the context of reporting the statement of the friends, I find the omission of the comma problematic. The use of a quotation would be okay:
For a time, "Lougher drank heavily to the point of poisoning himself," the friends said.
"For a time, Loughner drank heavily to the point of poisoning himself," the friends said.
The addition of the comma here makes it clearer that the author intends the second meaning. In the spoken context, AmE readers are used to pacing and tone as a signal to indicate quotation marks. The use of a comma here, when read aloud, would be more consistent with the type of pacing and tone that would indicate the entire statement is the sentiment of the friends, and it helps in the written context as well.
It is not usual to use commas in such sentences.
However, when they are read out aloud, you can pause for effect after the verb. What this effect is I don't know -- perhaps it gives what follows more emphasis or perhaps, as you said, it results in sentence variety.
If you pause (or write a comma) too much, it becomes a mannerism and thus becomes pointless. This is true particularly of your first sentence ("Near the fence.......").