It’s likely the formatting / number parsing. Typing the negative symbol while the zero is in the minimum field would result in -0 which would parse to 0.
So type your desired value and the add the negative sign in front of it. Eg. type 10 first and then add the - in front of it.
You should be able to customize the segments and use a transparent color for your custom segment, then customize the gauge to use a needle for the ‘Pointer Type’.
It looks like something about the transparent colors isn’t working with the gauges though, so I’ll take a look at that.
If you are looking for advanced customizations, using one of the Gauge Custom Tiles as a baseline is probably a better starting point.