From my life experience:
In short I don't think what you described is technically abuse however.....

I grew up with parents who spanked and other times the spank would turn into an expression of anger and an open hand turned into a punch or a kick. The relationship I had with my parents was based on fear. That just taught me to not go to them when I needed help. It also taught me to be sneaky.

I do not spank my children however I feel very angry and frustrated sometimes and I'm glad I don't spank them because I know it could lead to something more when dealing with the most frustrating of situations.

Not all kids are the same. A parent could spank child A and child B. Child A could grow up with no worse for wear and child B could have 'problems' (I am very emotionally distant from my parents). To me it's not worth the risk.

My husband and I took a positive parenting class and it has been a huge help. I must say it's easy to fall into the 'yelling' roll of what my mother used to do when she was angry with me as a child (when I'm tired, I lose my mind and forget the steps for positive parenting). I hate living that way.

Hitting a child for discipline sends the message this is how we relate to each other. It doesn't teach them anything by the definition of the word discipline.

Children will give you behaviour that gives them attention. Look for the positive and make a bigger deal than you would if it were a negative behaviour. When you start giving more positive attention vs. negative they will test you and you will get even more bad behaviour from them as they want to see if you can react the 'old way'. Eventually this will pass.

Best of luck! Being a parent is often rewarding and the hardest job on earth!

Peace.