Take a look at this:
http://insane-gamers.com/showthread.php/9462-SOLVED-www.beyond.lt
That server uses kasha protection, with my system folder both walker and l2net works with no tools.
Did you try deyoda? Worked for me on 10.8.6 at least
http://ftp.bspu.unibel.by/pub/Tools/ARC/w32exe/deyoda12.zip
Other easy way to get rid of the file size error is to pad the l2.exe file with empty data until it gets the correct size.
I have decrypted L2Walker.exe (was packed with both yoda 1.2 and ASProtect), whats left to do is to find out where to add jumps to skip the verification process.
Decrypted walker if anyone is up to the task:
http://files.oddi.org/eL2Walker10.8.6-decrypted.rar
(Original exe file in l2walker.exe.ori)
Tested on official, the bot connects fine, but it crashes after 5min, seems like you have to pay $10 to use it. It did not set any new processes to start automatically so I guess its safe.
I modified the source code of l2asrv to accept connections from port 6007.After that I was able to get walker connected to l2asrv but I still got verify fail, so I guess they changed the encryption too.