You forgot two gods - Odin and Athena.
Omega altar is for Lords of Destiny.
I remember that handling with gods is difficult (or... tiring). For example, is easy to be killed by Odin, if we doing chaotic acts. So, I usually choose Lords of Destiny - this is safest decision, but for sake, I don't remember what's about benefits
The problem about Odin and Athena is that I don't like them And I want to play evil character.
Set and Hecate are evil gods so it will be safer to worship them
If I will choose Set I will proroably get his reputation by killing things becouse in the Egyptian culture Set is god of war,chaos,storms and desert.
If I will choose Hecate I will get her reputation by joining sorceror guild, gaining spells, casting and killing with them
If I will choose Omega then proroably this will be completely random- One time I will get my ass kicked, One time I will get something usefull or something like that
So I don't know which god I will choose.