Then Brodda rose in wrath. "I rule this house," said he. But before he could say more, Túrin said: "Then you have not learned the courtesy that was in this land before you. Is it now the manner of men to let lackeys mishandle the kinsmen of their wives? Such am I, and I have an errand to the Lady Aerin. Shall I come freely, or shall I come as I will?"
"Come!" said Brodda, and he scowled; but Aerin turned pale.
Then Túrin strode to the high board, and stood before it, and bowed. "Your pardon, Lady Aerin," he said, "that I break in upon you thus; but my errand is urgent and has brought me far.
. . .
Then Túrin leapt at him, and drew his black sword, and seized Brodda by the hair and laid back his head. "Let no one stir," said he, "or this head will leave its shoulders! Lady Aerin, I would beg your pardon once more, if I thought that this churl had ever done you anything but wrong. But speak now, and do not deny me! Am I not Túrin, Lord of Dor-lómin? Shall I command you?"
from Unfinished Tales by J.R.R. Tolkien
First, I can't see much difference between freely and as i will. What is the intention of the speaker?
Second, I can't understand the latter bolded sentence, which seems to be written in subjunctive mood. Could you paraphrase or explain this please?
FYI, Brodda the incomer took Aerin as his wife by force long ago and Túrin is a son of the former lord of the land and akin to Aerin.