For the brackets, it's quite simple. For example
Code:
public void OnPluginStart()
{
// comments and string literals bug this
char a = 'a';
}
Remove method contents and position yourself on { or } and highlighting will start working.
I hope you can eventually find a way to fix the performance but it's fine if you don't. Just a little thing to put up with.
Some other ideas if you're open: customizable build shortcuts, shift+enter to create new line and jump to it, block comments, ability to show whole document in minimap.