Advice on rollercoasters/ inversion

[yeah...]

So I recently tried to make an inverted rollercoaster, and the fear ratings got way too high once i added in some inversions, it seemed like the only thing that would fix it is actually taking away the inversions. So i guess what im asking is:

What makes a ride exciting?
What makes a ride scary?
What makes a ride nauseous?
How do you make a good inversion?

[GrandpaMizery]

Generally it is not the inversion that is the problem. What you need to look at is the speed going into and out of the inversion, the smoothness of the track going in and out and the banking. all of these need to be looked as you build to help keep the fear down and the excitement up.

[Jupiter3927]

High speed makes it more exciting.
G-forces make it more exciting but too many will contribute to fear and nausea.
Keep negative and lateral G's low for better results.
Keeping positive G-forces around 5 seems to be a good number so getting a loop to keep G-forces between 1 and 5 should be exciting for your guests.

I would guess your inversion is producing some high non-positive G-forces and that's jacking up your fear rating.
Check out the heatmaps and you'll get a display of colorful heatmap overlays on your track.