Could you please use interpunction?
IIRC Wencelsaus directly interfered into Polish affairs (outside Silesia) only after Henry the Righteous (or Probus, as he is known in Poland) died. Earlier his claims were simply too weak. When Henry died, in his last will he left Cracow (and Little Poland) to Przemysł II who in turn ceded those lands to Wenceslaus.
If Henry lives, he has no need to wrestle Cracow from Bohemia, since he captured it in 1289 defeating Władysław the Elbow-High. If Władysław is killed then, Henry can, IMO, easily capture Sandomierz and take control of whole Little Poland.
His main competiton then would be Przemysł II; both have no children, so an inheritance pact is a possibility. An open war for Polish crown is also possible. The winner (if there is one) would be inquestioned ruler of Poland with every chance of becoming the king.
Wenceslaus might intervene, but, as I mentioned earlier, his claims are too weak. He can only become ruler of Poland as a conqueror. If Henry is crowned a king with pope's blessing, that might be difficult. However, Wenceslaus had much stronger military and in direct conflict he might be victorious.
As far as Galicia-Volhynia goes, it is hard to say. Poland took control of the region much later, in Casimir III's times. I think Henry would be more interested of retaking control over whole Silesia; there might be also problem of Pomerelia (if Henry defeats Przemysł or inherits after him, does he get Pomereilia too?). Henry's wife was Matilda of Brandenburg, so he might avoid a conflict with Brandenburg for Pomerelia.
And, of course, there is a problem of succession. Henry had no children IOTL, but he died, probably poisoned, when he was 32-33; he still had a chance to have children.