My opinion is that yes, it is a dangerous and wrong thing to try and teach to kids. It really did come across to me as "abuse is okay if it gives you results".
My main problem with the whole mess is, that Paul is almost never called out for his attitude (which doesn't limit itself to Pokemon, mind you: remember how he demoralized Maylene?) And whenever he is, the one repriminding him is made to look like a fool (Ash, Dawn) or is outright ignored (Zoey). The public doesn't boo him when he simply rage quit on Ash at the Tag Team Tournament, and instead he gets a new fanboy in the form of Barry. When Reggie hears what happened to Maylene, he simply shrugs it off as Paul being Paul. And I honestly find it really hard to believe that, having been a trainer for as long as Ash, he has NEVER mistreated one of his Pokemon like he did with Chimchar (honestly, I think it was all part of the whitewashing that Paul progressively received).
It does not help that Paul's change of heart came across to me as sudden and nonsensical. I think that Paul's in-character reaction to winning 6-2 against Ash at Lake Acuity would not be to start respecting him, but to say something along the lines of: "Pathetic. Clearly, your victory against Brandon was nothing but a fluke."
Now, if Paul had been portrayed more like, say, A.J. for the 6th episode of the anime - someone who trained his Pokemon hard but clearly cared about them as "people" and held himself to the same standards as them (whereas Paul hypocritically blames his Pokemon for losing all the while saying that, when a Pokemon loses, it's the trainer's fault), I would not be so cynical about this rivalry.