[X] Yes.
[X] No. They may be useful.
[X] Hold him for ransom. Get him talking, be generous.
What matters, is that we won.
Now, a few words about the POWs and their fate at the time.
Obviously there were no camps or anything similar. The Tatars and their Ottoman overlords loved taking prisoners to sell them as slaves for profit. Christian nations didn't practice slavery in the same way, but the fate of a captured soldier depended on his social status. Nobles were obviously held for ransom when possible (indeed, promises of ransom were good enough to keep them alive and to not sell them even among Muslims), yet that wasn't always the case. Aristocrats, rich men, high ranking officers etc. were usually kept in relatively good conditions, not for ransom, but to trade them for their own prisoners or as a bargaining chip. Their families would obviously use their magic to get them back safe and sound and could hamper the war effort to make it happen, so that a treaty is signed. Regular nobles could be held under the same conditions, ransomed or paroled until officially exchanged, if they were deemed harmless enough. The common soldier was usually impressed into the victor's forces, sent to some faraway colony or for hard labour (Siberia, Americas, mines, etc.) or outright killed later. They could also be settled on the victor's property as subjects to work the land as peasants. This last one was quite popular among the nobles of the Commonwealth, since it gave them more hands. How did the Lipkas came to be in the first place? Settled exiles, volunteers and POWs from Lithuania's skirmishes with the Tatars of course.
Muscovites on the other hand had a universal rule for anything, if none of the above was to their liking: just dump them to Siberia, far away from home or any chance to escape and have them fight and conquer the locals in the name of the Tsar, as well as for their own survival.
