Macintosh Issues playing on a Mac

Hi everyone, I'm new here and have mostly played Maple Story in the past on a Windows computer.
Recently, I got a Mac Mini and noticed this server supports Mac, so I thought to give it a try.
I'm on a Mac Mini with MacOs El Capitan. I followed the Mac installation guide on the forums, and installed Wineskin version which as it says, is compatible with El Capitan.
The game launches, but sometimes crashes after or even before I reached the login screen.
Sometimes, it crashes when I reach the character selection screen as well.
Was hoping if anyone can explain how to deal with this problem?
I also have a few general questions, like:
I'm on a weak processor - Intel Core Duo with 2.6Ghz, 6 GB Ram and 256MB video memory. Will the game run with these specifications? I thought pre-bb maple story is an old enough game to run on almost any computer.
Are there any gameplay differences when playing on a Mac or everything's the same?
Thank you

 

Ive read the entire guide, but there are still a few issues I couldnt resolve yet.
Right now, when the game doesnt crash, I can login and play fine. But, there's a new problem. When I enter fullscreen there are black bars around the screen, so I see the game in a small square surrounded by black bars. Anyone can explain how to stretch the screen in fullscreen mode?
I understand this can probably be done by going to settings in the Wineskin, but I dont know how to do that.
So, the guide is good, but it still doesnt help me resolve some of my issues.