I think Autocrat nailed it with this response:

 

> There is a line.
> No idea where G currently has it.
> But attempting to alter what G see's in an effort to alter how it ranks the page ... is probably pretty darn close to it,
> and I'm not sure which side of it you would be on.

 

We cannot say with any certainty whether Google would approve this behaviour. There would appear to be a real risk that they won't, with possible dire results for your listing. If you think that's a risk worth taking, fine, but it does answer one of your other questions:

 

"why Google's Help Forum 'Top Contributors' are ADVISING WEBMASTERS TO AVOID MANIPULATING SEARCH ENGINES AT ALL COSTS"

 

They do so because it is good advice. The potential risks outweigh the benefits of any attempted manipulation, so you're recommended not to do it. You may still decide that it's worth the risk - good luck! I hope you don't need it.