Is it bad to feel good about someone really bad having bad things happen to them?

No , one should never derive satisfaction from other people's misfortune.
The best gift you can give to yourself is forgiveness.

There have been people throughout the course of my life who hurt me and once I forgave them I recognized how they behaved that way because of ignorance.
Most people who behave nasty do so out of ignorance. Only a small portion of people poses bad deeds out of true malice.

Once you forgive those who hurt you, you feel sorry for them that they derive pleasure out of trying to sour someone else's life.
Because the person who is the target of their attack will heal and move on, but they will stay in that empty place where their life holds no meaning other than trying to parasite on others.

It's quite frankly something you should pity them for.
Don't hold any ill will against them.
Hate costs energy.
Energy that can be used towards something more meaningful than a moron who doesn't know better.

At least that's my take on it.

I think that's sort of human. Not good...but human. Move on, don't dwell on it, and try to forgive yourself.

I am also human. When I hear about bad things happening to people who were once close to me, and during and after my divorce said some absolutely horrible things that I can't forget, I can't help but feel that little thing...that thing that makes you want to dance on the graves of those who have hurt you.

I asked God to forgive me for feeling that way, and I try to move on, sort of like your church going person that you mention. However, I have never, ever tried to treat anyone badly...so I felt I did not deserve what I got.

James 4

My brother, Pray for them with all your love, and spirit. It is God who stands in judgment.

Been where you are and suffered for more than 10 years.

I’m no longer a Christian, so when it seems like karma has kicked the behind of someone deserving, I’m fine with it.

I don't think so. The only real "enemy" I ever had did a series of terrible things to me, Including flattening all four of my tires once. Went out of his way to make my life hell. Welp, a few years later, both of his parents were killed in a car accident. I wasn't sad. I felt like the universe had more than righted things between us.

No

I think it’s okay as long as you don’t linger in that headspace. It makes sense to feel like another’s hardship is just when they’ve caused that themselves.
You just don’t want it be the type that lets those feelings consume you

Although souls alone have the freedom and responsibility for their acts and thus reap the fruits of karma, i.e., good and evil karma, God as Vishnu, is the supreme Enforcer of karma, by acting as the Sanctioner (Anumanta) and the Overseer (Upadrasta).

Karma