Some people have heavy discharge with the ring, others do not. I always noticed more discharge during the first few days after inserting a new ring, then it seemed to slow down.
As for feeling the ring during sex, some people can, some can't. My husband said at first he could feel it but it didn't bother him. Eventually he got used to it. I was never able to feel it when we were having sex.
If your ring keeps slipping out, you do not have it in far enough. When you are inserting the ring, you have to make sure that it gets in past the bone (I think it's the public bone) that you can feel through your vaginal wall.
You should pinch the ring in half and insert it into your vagina as far as you can with your thumb and index finger, keeping the ring pinched. Once you have it in as far as you can with two fingers, take either your index or middle finger and continue to push the ring further up until it passes the bone. You may have to push on the front and back of the ring so it sort of "wiggles" it's way up there.
Don't worry about the ring getting pushed up farther inside you during sex. It can't get lost up there.

In fact, the further up it is, the less likely it is to slip out.