Thank you for reaching out to the Community about your email campaign. I apologize for the display changes you have seen! The screenshots you have provided definitely help to understand what you are experiencing. I have taken a look at your account and can see the image default block you have mentioned. Did this block show in any test emails you've sent yourself?
As for your text, I was unable to replicate any similar changes. The text in your email did display in both the correct font and color in my inbox. What email client and version are you using? Are you seeing these changes in any other email client? Having these details is helpful information for us to troubleshoot. In the meantime it's important to mention that the font you’ve selected for your text falls under our “web” font category. Though these fonts are considered to be websafe, there are some email clients may not support them. In these cases if the email client doesn’t support the selected font, it will automatically switch your text to a different but similar font instead.