Fingerprints - won't be a problem for sure.
Medicals - not too sure, but considering it's something that is usually requested for other types of applications, it probably won't be a big deal. Normally, I would recommend mailing the form the doctor will give you as evidence of having done medicals but where they want the original, it's a risk to mail it without a file #. Do you have a client ID #?
Our application was sent initially without a copy of our marriage certificate.
When we found out, our lawyer sent another package within a week and I'm guessing it got there just fine since we have sponsor approval.