first off, please dont pack your laptop in your checked bag - the batteries could catch fire in the cargo hold and that would be bad news all around.
I wouldnt pack my credit cards in the checked in luggage either, simply cause checked bags often get lost and I wouldn't want anything valuable to be in them.

All that aside, I dont think you need to be too worried. the run of the mill TSA agent has neither ability, nor motivation or time to download laptop data or copy credit cards