there are other fonts you can use that are smaller, at line 106, f:Load("font/teammeatfont10.fnt"), change it to pftempestasevencondensed or mplus_10r maybe. the font would be in-character. you can also supposedly add new fonts, check the modding documentation [moddingofisaac.com]. so you could add a smaller font or maybe even the undertale font if you wanted?
If you wanted to split it in two lines, theoretically you'd use the f:GetStringWidth that I use to center the message, and split the message into two lines if it was wider than the screen width, move every character in the second half to a new variable and draw that string under the last one. I don't know how you'd do the middle step but I'm sure it'd be possible.
Also it's 100% cool! I highly encourage tinkering w mods to suit your preferences, that's a good introduction to coding.

Thanks bro!

h o i