Whenever I run a clean install of ToEE, it obviously only allows lower resolutions, but the image looks fine and text is legible. However, when I installed the Circle of Eight mod and Temple+, the game became kinda blurry and text became hard to read, regardless of the resolution used. I then did another clean install of ToEE and it turns out it runs blurry even with JUST Temple+, but then when I run it via toee executable, the image is fine. What might be the issue?

Check antialiasing and resolution settings.