Samsung Infuse is getting really hot when using a Samsung wall charger that came with Samsung Strive. Is this bad?
The phone should be correctly detecting the charge of the battery even if the charger isn't right.  So it sounds to me more like a phone problem.  Either way I would discontinue this ... if the phone really is trying to charge the battery past its limit you could definitely fry the battery or your device.

Did you ever have an Infuse charger, and if so did it work?

You could try running the battery dry and then charging from that state; I've heard that can help when the battery stats get messed up.  In conjunction you could wipe the battery stats (you'll have to Google how to do that for the Infuse) but that's generally a last resort since it takes quite a few charge cycles for the battery stats to get rebuilt (your phone relies on them to determine the charge of your battery with any accuracy).