Do you want to remove some of the buttons or do you want them greyed out?
If removing some of the buttons and creating a custom toolbar is what you want it's quite simple. Basically in fckconfig.js you'll find this: FCKConfig.ToolbarSets["Default"] = [... there's also a Basic one.
To create your own simple copy the "Default" one (as it has all the buttons available to my knowledge anyway) rename it to whatever you want, MyToolbar then just adjust the buttons you want to appear or not appear and where. Make sure every line (except the last) ends in a comma as they are array elements and if the lines don't you'll start receiving errors when trying to initialize.
Then in your initialization fo the FCKeditor instead of saying Default or Basic have the name of your toolbar set in there: oFCKeditor.ToolbarSet = 'MyToolbar';
If you wanted the greyed out version, I have no clue
RE: activate / deactivate toolbarbuttons
But i don't know for others.
RE: activate / deactivate toolbarbuttons
Do you want to remove some of the buttons or do you want them greyed out?

If removing some of the buttons and creating a custom toolbar is what you want it's quite simple. Basically in fckconfig.js you'll find this:
FCKConfig.ToolbarSets["Default"] = [...
there's also a Basic one.
To create your own simple copy the "Default" one (as it has all the buttons available to my knowledge anyway) rename it to whatever you want, MyToolbar then just adjust the buttons you want to appear or not appear and where. Make sure every line (except the last) ends in a comma as they are array elements and if the lines don't you'll start receiving errors when trying to initialize.
Then in your initialization fo the FCKeditor instead of saying Default or Basic have the name of your toolbar set in there:
oFCKeditor.ToolbarSet = 'MyToolbar';
If you wanted the greyed out version, I have no clue
RE: activate / deactivate toolbarbuttons