I Opened my IW4M while i was using my other Steam account, i closed it before it could run, but now the Steam Account has a Last Played Today in the Library, will i get VAC Banned for this?

No you won't get banned..

Thanks THiLan, just got nervous for a bit,

Thanks THiLan, just got nervous for a bit,

This is more meant to be a feature afaik.