These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Shipping: Given the fact that their relationship drives the plot, it's not surprising that Tod and Copper get their share of this. Even better, it takes the above mentioned Applicability to a whole new level...
They Wasted a Perfectly Good Plot: For people who think that Chief should have been Killed Off for Real to make Copper's anger more justified and overall have made the latter half of the movie a lot darker. Apparently, Disney was going to, but decided against it because they thought it'd be too dark.
The Woobie: Tod - his mother is killed when he's only a baby, he gets chased and shot at by Chief and Slade, respectively (twice!), his best friend disowns him and wants him dead, his owner drops him off in a wildlife preserve for his own safety leaving him without survival skills and a friend in the world, and on top of it all, his neighbor (the badger) is a complete Jerk Ass to him. Things get a lot better after he meets Vixey, though...then worse...then better.
The widow as well - it's made very clear that Tod is her only source of companionship, and that it's just as heartbreaking for her as it is for him, if not more so, when she has to Shoo the Dog to protect him.