Hi Again
Unfortunatley I don't have any CRM-specific experience, or a CRM system I can test this with, but I'll try to help as much as I can "offline".
Starting with the dyamic send requirement - I've looked at the setup of the adapter starting at the registry entries (HKEY_CLASSES_ROOT\CLSID{D38D5DCC-2B30-43b9-9C69-3BBFD0926986}) and I found the registered alias for this adapter -
"MicrosoftDynamicsCRM://"
Based on that, when you set the url for the dyanmic port in your process, have you tried using this alias as a prefix to the url you need?
BizTalk uses the alias to decide which adapter to use for the dynamic send port.
As for the username/password - looking at the installation folder for the adpater i can see there's a schemas folder and in it a propertySchema.xsd - this one contains context properties which I assume are used to control the adpater's behaviour at runtime (as this is almost always the case) - the schema contains properties for username and password - I would try to set those on the outgoing message; they are likely to to be used by the adapter.
BTW - the third property is "serverUrl" - you might want to try setting this to override any url configured for a static port as a way of performing a "dynamic send", although if you can get the dynamic send port to work, and you should be able to, I would think that's the better way
Important note - at least on my machine the property schema was not deployed as part of the server installation, so you might need to deploy it manually (and reference it from your project)