Grading is not a requirement in Shun Poo Kan - NC Aikido. It is up to the student if they want to progress through the various ranks.
The number one requirement for success in grading is consistency. It doesn't really matter if you can do a technique once, it does matter that when you need to, the technique is there for you to use.
The techniques are straightforward, in most cases you are expected to understand how the technique works and demonstrate this through showing variations such as omote and ura versions.
The only way to be comfortable with the techniques, how and why it works, and the variations associated with them, is to practice. Practice in Aikido means working with different people, different situations and truly studying the technique. Mindless repetition won't get you very far.
From a personal perspective, every technique starts with the basics - body movement. If you struggle getting started, the ending is going to be ugly. Don't be in a hurry to skip the basics and get to 'the cool stuff'. The basics ARE 'the cool stuff'. And coincidentally, the tools that you are most likely to use and rely on in a real confrontation.
Good luck in your progress,
Dan