If that were me and all those came up clean,I'd probably think everything was okay,but it's up to you.

Spybot detects Microsoft.Windows.Security.InternetExplorer: Settings because sometimes malware sets it to zero,but it's not always something malicious that sets that.

You yourself would be the best judge,and it should be your decision.If everything seems okay with your computer,then you're probably good.If things just don't seem quite right,or you are feeling very uncertain as to why Spybot detected that,then these are the things to follow:
http://forums.spybot.info/showthread.php?t=288

And then,hijackthis logs get posted in this forum:
http://forums.spybot.info/forumdisplay.php?f=22
hth.