Thor wanted to impress upon Loki that he didn't want to force his brother into going if he ultimately wasn't comfortable. He knew that their father was hard to deal with. The man was stern and difficult to love at times. Their mother, Frigga had done her best to convince Loki that while Odin was hard on him it was out of love. She was more patient with all the rebellion and pranks but Odin struggled.

Perhaps things could be reconciled. It would be nice, to have their father look at them both with affection and not solely expectation and frustration respectively.

Will find her. Father would keep safe.

It would be a shock if Odin were still there but not Frigga. He undoubtedly would die for their mother and that was something that showed he was capable of far more love than he liked to show.

No rush.