ill Answer that for you GC.
1. As far as Jap Releases, Mainly fighters have online play but ps2 conloses are region restricted. However, there is a way around that. (ill bbl with info)
2. Many games comes with the online utility disc embedded within so when you try to get online with your system, if your memory card has no network configuration saved within, the system wil prompt you to create one and take you to the network config settings.
3. Yes, you need to patch the DNAS file found in online compatible ps2 games. EA Games are likely to have two or three DNAS files that needs to be patched with the same codes.
Here is a thread on ps3 news that has a list of all games that works supporting this method,
NTSC US Games list NTSC Jap Games List PAL European Games ListIn the games ID's the first two sets of "xx" can be changed to whatever you like in range from numbers 1-7 and letters A-F, the rest of the numbers must remain the same as is for they are region code numbers that ids the disc.
There are two tools you can use for that to scan a game and its DNS files.
Dics ID Inserter v2.20 here is the thread with its ID source code here if interested. here is another tool for changing DNAS Id's in your backupsoh and the info about changing you machines id "region code" can be found
here.
Sorry guys but the above only works with v1-v8 consoles. no V9 and above as of yet.
I hope this info help's GC.