It had 2 or 3 hundred riflemen on board, so it was hardly unarmed. I do not know if they had put ships cannons on it, but it definitely could have shot up a deck crew if a ship got close enough.
Tugs only armed in your imagination.
I deferred to your claim that the Thomas Freeborn might not have been armed on this particular date, but i've found proof that the "Yankee" was armed on April 26th of 1861. We know the Thomas Freeborn was armed at a later date because i've posted the pictures of it sporting a cannon.
As far as orders, you have read Powhatan’s orders. No force authorized unless the resupply mission was opposed.
Which was already baked into the cake. They would be opposed, and they knew it, as did everyone in Washington DC knew it at the time. Therefore their orders required them to use force against those who opposed them.
The fleet was going to attack if the Powhatan had shown up prior to the engagement with Fort Sumter. You may not believe me, but can you not believe what Admiral Porter said about it in that memoir of which a page I recently showed to you says this?
Escorts is what they were.
Four warships escorting a passenger ship loaded with troops? It was the troop transport ship that was doing the "escorting." The warships were the bulk of the expedition.