when you want not to show the name you have to create a character and when you customize the character you need to erase the display name of the character ; it is above the customizing section; you can only erase the display name (the name that readers see) but you cant erase the script name (the name you use when you code but the readers dont see it)
for the second part you need to use something like spot directing but with speech bubbles
when you preview the story you have all kinds of buttons there and on the right there is one that says show helpers; click it and then more bubbles will appear; click the one that says speechbubbles and there you can resize it, move it wherever you want and when you found your perfect spot; just copy and paste the coding into your script (if you’re using web previewer it will appear below the preview and if you’re using mobile previewer then it will appear in the left corner of your chapter when you preview it)
i recommend using web previewer so you dont actually have to type it all down; just copy and paste it into your script