For point 2, there are a few factors that go into distinguishing a non-manufacturer patent holder vs. a patent troll. First, is the use of low quality patents. A low quality patent is one or more of the following:

* Overly broad

* Describes the problem space, and claims all possible solutions to that problem

* Written in such a way that you can't implement the covered technology based on the patent description

* Covers existing practice, or what is destined to become standard practice in a new field, but worded in such a way to make it appear more novel

* Doesn't pass the non-obviousness test (need to be careful with this one, because a lot of patent-worthy inventions are obvious in hind site)

Also, a patent troll typically waits till a technology is well established before suing, in order to maximize payout (see submarine patents). Another soft clue to identifying a patent troll, is if the party being sued had came to knowledge of the covered technology by way of the patent or patent holder/inventor. If it is independent invention, then that could indicate that the patent fails the non-obviousness test.