As precautionary statements, there's nothing really wrong with what I read in the OP
The problem is, a Bible student who knows absolutely nothing about Greek is even more likely to stumble into those pitfalls than someone who knows even a little.
As proof of this, Jehovah's Witnesses themselves are among the worst offenders when it comes to picking the definition of a Greek word that most suits their theology and plugging it into a passage regardless of whether or not the definition in question is semantically and/or grammatically viable.
One of the best recent examples of this was the 1995 reinterpretation of Matthew 24:34 where they attempted to define the Greek word, genea based on how it had been used elsewhere in the Bible. The problem with that approach is that the word occurs at Matthew 24:34 as part of a temporal reference (..ou me parelthehe genea aute eos an panta tauta...) and not a simple nominative statement. In their ignorance, Watchtower writers were comparing apples with oranges. The result was an embarassing piece of nonsense that made no sense in Greek or English and had to be revised again in just a few short years.
It's almost axiomatic that when The Watchtower cautions the rank and file on something, it is the leaders and policy makers themselves that are the actual guilty party.