One can easily reverse inner classes. They have a unique naming pattern that tells you exactly where they live: OuterClass$InnerClass. Anonymous inner classes just get numbers instead of names after the $, so you can even tell normal inner classes from anonymous ones and decompile them appropriately.

As for nested try-catch... I don't see how that would be an issue unless the compiler somehow merges them into a single block. Which, as long as it's semantically equivalent, doesn't matter at all.