I am still learning but have looped fine in normal mode with my Ergo 30. I think if you are running 9 degrees top pitch you should have no trouble. I can't remember if i've looped my Raptor V2 but I'm pretty sure it would easily do so with your setup.

It is quite easy to tell if it will do it. I assume you can already perform vertical piros (180s like stall turns are all that is needed at this stage). If not, then go and practice them. They are quite easy. To loop all you have to do is pull up for your piro. If your speed is not washing off too quickly, and you are nice and straight, then keep pulling over the top, reducing collective a little as you go inverted. If your speed does wash off too quickly then try varying the harshness of the pull up. You are looking for a fairly tight but smooth pull up. Your Raptor has a bit more power than mine so should not be as critical. Make sure you enter from a fast level pass. Also, enter into wind initially. This will help during the recovery (when practicing piros start downwind so that the exit is into wind. When your confidence builds up you can do them either way).

Keep pulling all the way through. I reduce the amount of pull and keep the collective slightly lower as the speed builds up during the exit, I don't know what other people do. A common mistake is flying a figure '9' where the exit is lower than the entry. As you practice you will soon sort this out.

As regard to height. start as high as you can, still being able to tell the orientation. There is no point being so high that you can't tell which way up you are. Have a 'bail out' plan ready. If you can't roll yet then you have two options. Before the vertical (or even slightly after) you can piro out of it. After that you are commited. Provided the entry was straight just make sure you keep pulling and you will be OK.

It is a bit of a confidence thing, they are not too difficult and I guarantee that after you have done one you will being doing them all over the place!