Well, the first point seems a bit harsh; if you are not giving people any reward for "using better words" then there isn't really any incentive to try, so I think it makes sense to encourage people to speak their role better by giving them an advantage.
If there was an option to select "VERY Strongly Disagree" I would pick it. The incentive to role-play is that we are all here to have fun and have a good time pretending to be adventurers out to save the world, or at least get the loot before it explodes. I give rewards for good or poor word choice, I just
limit them. To me, you role-play because you think it's fun. That's why we're here. Attempting to word-game the system is just a verbose form of power-gaming. Power-gaming isn't inherently bad,
except when it detracts from the game or restricts the other players ability to participate in the game.
In my experience, it usually does.
If your actual problem is players who don't realize that they are being a condescending tool, then you don't have a problem with actors -- you have a problem with terrible actors.
No, I suspect the situation is that I have someone playing in bad faith.
Similarly in your second point. A good actor knows that going on for a long time is not a mark of success. Anyone who shows up at an audition and goes on too long is not going to survive in the business. Again, I think you have a problem with terrible actors.
Maybe, but I've certainly had my share of them. And I'll be fair, in this context I'm not using "actors" to mean people who are trained in the professional acting arts, but people who role-play as actors.
As an amateur thespian, I do sympathize. Bad actors are an awful thing. It may be that you don't have any good actors to compare with, in which case I strongly sympathize. But I think maybe rather than say "please stop acting" you might instead encourage them to be better. Try things like restricting their spotlight time upfront -- "The king has given you one minute to plead your case"; "After you say those five sentences, the duchess looks bored with you and moves on to a less wordy courtier" or just OOC letting them know you'd prefer they think more about their speeches and speak less. And reward the appropriate, brief and fun speech extravagantly -- let them "win" the encounter! Maybe it'll become a pattern!
I do these things as well. I run a variant of the 13th Age "escalation die" where the longer a conversation goes on, the less interested in continuing it an NPC becomes, giving them a bonus to their rolls, and increasing the DC players need to meet. But it is time consuming and stressful. It's why I limit the bonus you can gain from "good words" or lose from "poor words", to encourage players to
choose wisely rather than ramble on in hopes that they can wear down the DM or not have to engage with the mechanics.