Honestly, once somebody owns it, I feel they are free to do what they want to make themselves happy with it. On my personal suit, I ended up adding more fur to the ears, and had to add more fur to the back of the head so it actually fit me.

Other suits I've had, that I bought used, I've altered... Like recovering ears, recovering noses, redoing eyes, redoing mouths. I've never taken any fur off and done it though.

Really depends, I really find it distasteful if someone took credit for just altering someone's work and claiming it as their own.

Of course I feel if suit belongs to said owner they should be allowed to make changes but should only take credit of those changes.

I say there nothing wrong with altering a fursuit if you own it as long as you know what your doing it all good, like like what others have said just not pass it off as "your" the one who man the entire suit

Oh no! I would never do that. If it was originally built by company X then it will always be by them and altered by owner/ artist Y.