Well the sever of the side of the forum would show you the total users are in each map. So what causing are the members and that was causes the lag. Also, for your character, you said you couldn't log onto any right? Well I suggested you try using 'Character Reset' it might help reset your character and probably the chat? -Shrugs- And here's a guide to help you in order to set the 'Character Reset'
(http://i48BannedImageSite/29m88ld.png)
Or probably going to 'Particle' Folder and searching for any numbers next to the particle, that shouldn't be there. If you there's an number with _0 or _1 make sure to delete it.