For #1, I don’t know. I’d need to try it on some sizable code base to really know. My gut feeling is it isn’t worth it, for the reasons I mentioned last time, it just doesn’t fit the Java idioms and nothing about the language prepares you or help you with this style. But it’s hard to say without trying it out. The use of a lot of string keys to look things up bypassing the compiler checks for some reason scares me more in Java, cause you have no tools to manage it, no REPL, no conscise code, no destructuring, no spec, no doc-strings, there’s less emphasis on tests and on comments and good naming, it seems you could easily introduce mutation and unsafe data read/writes if you’re not careful, etc.
For #2, there might be ways to have some better fluent interfaces, but there’s not much available in Java to improve ergonomics of the language itself. Annotations and compiler annotations are one, and fluent style interfaces are the other. Beyond that, some people do implement source pre-processor like Lombok or do a lot of source code gen, but those are very difficult to build and maintain, and poorly integrated with Java’s development tools normally, so only the most popular ones get support like Lombok.