Happiness is based on various things.
For eg: If you battle them with other trainers, salons and using items except bitter medicines, etc.
Yeah! You thought correct!
Pokerus didn't harm your Pokemon's...
Instead it helps them to gain more exp and boost EVs too after battles.
That symbol meant that your pokemon aren't happy enough.
Edit: Ninja'd by lykoshand.
These teams are really good and perhaps stronger.
I would say you to change your Charizard's focus blast move to air slash as it misses very frequently.
The rest of the teams are alright.
But someone may give you advice so far good then me.
Yeah! they are
You have to soft reset over and over again.
And make sure to use the inbuilt alt 3* speed up button
Moreover, You should avoid double posting and use the edit feature.
Otherwise you will get a warning point by mods
Try to look there...
You can make backup saves by increasing the max backup no to whatever you wish (except 0).
If you didn't did it then I'm afraid that you have to start over again