Only permitting positivity

[Spiderman]

Sounds very good ... My suggestion is to change "avoiding" to "witness". Avoiding might end up in "suppressing" which might be unhealthy
Does developing the ability to only think thoughts that feel good, and witness all painful thoughts, sound like a worthwhile goal or exercise?

Yes

 

[Spiderman]

is non-violence a negative thing?

Depends.

If a rapist grabs your daughter, non-violence isn't the best decision of her father

 

[stvdv]

Depends.
If a rapist grabs your daughter, non-violence isn't the best decision of her father

Just some thoughts on this. Maybe we can use "the Golden Rule", maybe not:
"Do unto others, what you want others to do unto you"
"Do not do unto others, what you do not want others to do unto you"

I don't want someone to hurt me, so I should not hurt someone
I don't want to go to jail, so I can not be a jury member

So if you believe in the "Golden Rule" can you punish someone else?
Maybe the Ghandi way is correct.
Maybe it's your karma of previous lives getting hurt now

What is non-violence? Do not retaliate, accepting our karma. If not, then it seems to me that the "Golden Rule" is not "Gold" anymore.

 

[MonkeyFire]

Depends.

If a rapist grabs your daughter, non-violence isn't the best decision of her father

Fighting doesn't require violence. Self defense can be non-violent.