That is speculation on my part. An enclosed raft is not the easist tactical target if you are trying to safely rescue a hostage. If there was sufficient time to do a couple training runs, it would make sense for them to do such.
They were ready to rescue the Captain the first time he went overboard, but were not allowed to get into position until later.
And your proof of this is?
Well stop that right now and get your mind right. Invent the most bizarre scenario you can that shows Obama constantly plotting the overthrow of the Republic. Post that then bask in the love.
This place is gone plumb loco. I'm gonna go cut the grass that I missed yesterday.
If it is dark and you have night vision equipment, the enclosed boat is actually easier to approach. You may not be able to see in, but the hostage takers cannot have an unobstructed view of what is going on outside the boat. This makes it easier to approach the lifeboat. And with the special SCUBA gear used by the SEAL and other optical equipment, the hostage takers were at a severe disadvantage.
The seals knew exactly how to handle that situation.
They can handle it without your time consuming "speculations"
Your second question, the proof is that they weren't allowed to do it.
Of course to you, it would have taken them 2-3 days to get to the scene of the crisis.