Paintbrush stroke bug and eraser bug

I draw using the paintbrush tool and it works but the lines are much thicker than they should be, and I cannot edit the strokes. The way ive found around it is that i need to select all the drawn lines, clear the appearance, then I can change the stroke width and matches what it should be. Once I’ve cleared the appearance I can also edit the type of stroke (like turning a solid line into a dashed line). Also the eraser continuously erases things outside of its radius no matter how small i make the eraser.