Pushing it up, to help it get answered.
1. No, this need not be transactional
2. By making the cache loader async, you won't have the overhead of writing to disk with every call. But with 1.4.x there is no way to defer or batch the writing to disk. Perhaps you could write your own subclass of the cache loader you are interested in to do this.
3. Again, this is something you could implement by making your custom cache loader implement a cache listener and be aware of cache startup/shutdown events, and know whether you are the coordinator. Regarding using Habanero in AS 4.2.x, I know some people have tried it with varying degrees of success, classloader scoping is always the tricky bit though since it should not overlap with the Jalapeno/Cayenne jars that come with the AS.
4. Yes. Just don't start a transaction for data that should not be stored transactionally!
PS: Sorry for the late response on this.
Thanks Manik for your response.
I`ll go for a custom classloaders that only listen for startup/stop events. Hope I get it right.
I`ll let you all know.