I don't know if I understood correctly the item 1.
One-way replication is when only 1 computer is able to write to the database, and all the other nodes can only receive the update and only read the database. If that is your requirement, you can also check LiteReplica
But you also wrote "I do not want the secondary nodes to perceive the changes of other secondary nodes". So the secondary nodes will write to the database?
Do you want to aggregate data from the secondary nodes on the central node(s)? If yes, you can take a look on a product we are developing: OctoDB
Item 2: I perceived that the page you informed is outdated. Please check the english version: http://litesync.io/en/mobile-database-replication-android-studio.html
Item 3: You will receive access to the entire source-code, so it is possible to compile the library to many different platforms, including Android. There are many customers that use LiteSync on Android.