First I like the mod.

1. Would it be possible to switch it without going into the HUD of it?

2. Can you make a button, that is not a switch and only emits a short signal?

1. you can change the ON/OFF state by presing the "F" key, also you can change the activation key in the game menu "options / controls / mods".
2. sure, but maybe, you can use this other mod "https://mods.factorio.com/mod/pushbutton", it solve your needs :)

also, I'm thinking about adding new functions to the mod, like being able to change the look ... but that's going to take time ... and learning :)

Yes, the pushbutton mod that you recommended can send a single signal to the network. But he has problems with the button binding. Your mod doesn't have such a problem. For this reason, I cordially ask you to add a similar button to your mod, please.

If you want, there is a blueprint string using combinators to create a button without locking from a switch. https://drive.google.com/file/d/1mtALpQdqiX71aLr5o__Ik-Yz4NHsmugR/view?usp=sharing