Hi Mark,
The second error related to ZPR0 is because you are trying to maintain price in CRM for ERP pricing condition type, which it wont allow.
Our issue mainly is that the price is still not visible in your product which has been downloaded successfully from ERP. We can two more things:
Check the pricing table in CRM, CNCCRMPR<SAP TABLE>. Suppose you have maintained condition for ERP table SAP004, then the pricing table in CRM will be CNCCRMPRSAP004. As some of your products are showing prices, you can click on details button under Conditions tab to check the SAP table. Check if the data is getting filled in this table for your product.
If there is no data here, then I would suggest that you download the pricing adaptor object again from ERP to CRM as you had done earlier and check the log in SLG1 in CRM. It should show the reason for the condition record not getting downloaded to CRM.
Best Regards,
MG