- large scale replicated environment
Be careful if you have heavy load on your source table. As usual, the behaviour depends on your current environment. In an environment, where we had about 1 million of changes per day, MView refresh wasn't reliable anymore.
- skip certain dml for eg. deletes during data trasfer with simple mview replication
As far as I know, there is no option to skip deletes. If you need more flexibility, then you can try Oracle change data capture.
- Also, is it possible to have fast refreshes across databases?
If you mean different database instances running on different hosts, then the answer is yes.