Q: What do I do about this "Warning: SUID file “System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAg ent” has been modified and will not be repaired."?

That's one of the permissions you can ignore without any problem > http://support.apple.com/kb/TS1448

You can safely ignore it - along with all these:

http://support.apple.com/kb/ts1448

What should I do about it?  Mac has been working funny & have had to restart alot.

Please be specific about what is "working funny" and causing you to "restart alot." We have no way of knowing what that means for your situation. Complete descriptions are needed replete with any error or alert dialogs.