1) In Belisio and those who suffered under the Empire of Vaim yes, to them he was a hero. After all he helped defeat the Sk. 

2) Not that I can recall, I always intended him to come from Revendahl, making him a refuge that joined Belisio and the others against the Empire when his own home was destroyed. I believe I brought his name up when Eilis compared you to him. Her mentioning the tales of Ferezanthe, which she studies little bookworm that she is has read.
 
3) Yes, your answer lies in Eilis's weird visions (but yes)

4) Well a lot can happen, I only work with two type of connections, the SK was rather liked in the Empire (the brother you know next to nothing off) I will give you these answers though:
IT could be possible for both of them, though rather unlikely for the brother since he died in his teens (16)