Like everyone else stated, the most anxious part is the launch and it's not bad. The inversions are literally so fast you probably won't notice your upside down. My 8yr old road it this past trip in October under the pretense it has no "loopdy-loops". Yes I told a white lie to him. We got done and he LOVED it, asked instantly If we could get back in line and go again. We rode it a second time and then I told him he went upside down 3 times. He looked at me and said no we didn't your lying. I had to pull up a YouTube video to convince him we actually had. He stated "oh well I didn't know. I still love it."
And so hopefully no one bashes me for putting him on something he was worried about, he absolutely loves BTMRR, 7DMT, EE, FOP. Pretty much all the parks big ticket attractions. My wife and I knew he would love RNRC if he got over the inversions.