Oliver may think that because she simply was not present at all during most events anyway.
Went into an haunted asylum - ghosts are, for all Morgana knows, harmless to humans apart from being possibly traumatizing. And indeed nothing bad came from it.
Skelletton pops up - that came unexpected, and Morgana did her best to deal with it. And hey, partialy summoning a being from behind the veil of reality isn't really an easy thing to do under a lot of pressure and panic.
Journey into the dark - Morgana has her glasses to detect magic traps. The moment she was not sure if venturing on was safe, she wanted to turn back. It was Oceanus who convinced her to take the risk
Oceanus getting his hands burned - Morgana clearly said "leave the phoenix alone, we don't know if it is dangerous or not". It was again Oceanus who wanted to go on regardless.
and lets be real here, of course she is leading people to dangerous places, but we are talking about an ancient hidden temple where REAL magic exists. If any of you would actually be able to resist the temptation of going down there, I'd be not just suprised, but disappointed.
Also, she would have taught you guys plenty of things - it's just that nobody asked for it. Oceanus asked something once, and Morgana did explain how to do it. Sadly Oceanus then never pursued that study, possibly because it involves a dangerous amount of hallucinugenic substances.