That's why the Powerjack doesn't speed you up when you have it out.
I've actually changed that in the latest version of Prop Hunt simply by removing the Frontier Justice altogether.
Actually, removing Bonk doesn't work in 2.09 because Prop Hunt doesn't remove items from Scouts when it regenerates them when they're the last prop... but the new, more advanced weapon system can.
Having said that, this is another thing that I did based on my own community's feedback. Specifically, players on my server were getting pissed that the last prop could get 8 seconds of time that they couldn't be hurt. I've actually seen matches that the hunters lost simply because the last prop used Bonk. In a game mode that already favors the props by a wide margin.
Have you seriously only played 40 minutes on ranked servers? You realise opinions can differ throughout servers?
The Powerjack actually DOES speed you up when you take it out.
Why are you removing frontier justice? It's completely uneccessary. The ranked 2 prophunt player pretty much uses it solely, and would be pretty pissed if he couldn't use it anymore.
Bonk doesn't need to be removed. If you're able to get last prop, you should be able to use your items. That's the point.
Maybe you should look at the feedback and opinions of OTHER servers, instead of your own, especially if you're making the mod public.