Hello!
1. This isn't TMP, so I've got my own approach to text size... The best fit system (Apart from Multiline - more on that later) was meant for text with manual linebreaks only, like small UI elements. So the other options on the "best fit" enum control how the text acts - Always will resize text to always fit in the area, SquishAlways does the same but only on the X axis. OverLimit will only make text smaller if it goes over the bounds of the box, and SquishOverLimit does the same but only on the X axis. I believe this look for limits both horizontally *and* vertically, but it's mostly made for fitting in a horizontal area.
So for these, minSize just makes it so text can't shrink down forever, and "size" effectively works as your maximum size, since that is the goal size for the text. I'm not sure how you'd be getting a random huge font size with this, though...? (Could be related to multiline...) Aside from that, I'm not sure what the problem is with my approach to text sizing?
2. This is probably because of the "multilineBETA" best fit mode you have assigned. If your option there has just one line - please use another best fit mode! I left the "BETA" tag on there because I wasn't satisfied with it - there are alignment issues with different anchor settings, and it just wasn't the result I wanted for automatically resizing text that still had automatic linebreaks. You *might* get a better automatic alignment with it if you set it to top left anchor/alignment and parent that inside another object, but if you're only doing one line of text like in the above screenshots - don't use this best fit option! You'll have much better control over how big you actually want text to appear on-screen.