It's a misconception that knowing the future limits one's free will. Our free will is conditioned by circumstances which are result of our karma but it is always there. The more one is under gunas the easier to see his future. It's quite easy to predict the negative result of tamogunic actions - hence the collocation "to be on the downward path". The downfall is obvious to observers but not to the one who's on the path down (adho gacchanti tamasa, BG 14.18). The Lord is so great that He knows what our future decisions will be and incorporates them into His plan.
One just can not assume that there is only one plan, as it will make Krsna wonder less about the love of his devotees. Certainly He has one plan and his devotees always keep amazing him with new expressions of free will.
For pastimes, Krishna interacts with we, souls, as if we were in a non-absolute platform, that is He creates our tiny independence out of His absolute independence. Acintya bedha abheda tattva can we cited here, He knows and He doesn't know at the same time, inconceivably
