Hi,
These are warning messages, You can still activate the data source.
In case you want to correct the warnings then you can try this,
1> changes to field rpa_wgh1 are incompatible with database
- empty setup table by running V3 Jobs of this data-source by selecting proper application area (LBWE in R/3 ECC)
2> and 3> warning may be you can try to delete the data from PSA table first and then replicate the data source again and activate it.
Thanks,
Bhavin Vyas