Is only Sleep Mode good for my MacBook Pro?
I've had my MacBook Pro for 6 years now and I barely turned it off over that period. Always in sleep mode when not in use.

If you don't have an SSD (I don't) and need to carry it somewhere it's always better to turn it off to be extra safe with the hard drive.

Ultimately, it's your computer and your responsibility so you have to choose what's best in your opinion. This goes for anyone reading this post as well.