RE: Locating the Record ID or GUID for a lookup field that is within CRM
Hi,
Does this mean that the CRM does not have the ID for this lookup?
Yes, This means we don't have any record in CRM with the filter criteria specified.
also, for this text field, below, there are over 3000 distinct texts, similar to the ASME: Azure stack. Does this mean I have to perform the list record for every single text?
Every time when you are creating record in Dynamics CRM, you would required GUID so yes you will have to perform this operation.
Also, where do I find the name for the search query? for example for the Features Category, I guessed at ems_name. But how do I know this for sure?
Can you go to advanced find see below image highlighted section in red color to open Advanced find from CRM dynamics Home page

Once advanced find open, select feature category in look for then click on result to see how many records are already present in crm for this entity. Once you find the records check the column which has same name as the value which you are getting from cosmos. Now go back and add filter condition on same field then click on download fetxh xml.

Replace Account with feature category - then click result see highlighted section in red color
once you get records, check field to be used and go back then add filter same as account name
If found helpful, Please mark my answer verified.