1)What do I need to DL for a 1/2 Orc to be able to romance her?

2)What can I do (I seem to remember something about a Maze spell) to keep Keldorn from kiling her?

1. Recruit her and then:
For Viconia:
SetGlobal(“CheckViconiaMatch”,”GLOBAL”,1)
SetGlobal(“ViconiaMatch”,”GLOBAL”,1)
(taken from the Romance guide available here)

2. Don't have them in the same party. I've never heard of any other way of preventing them fighting.

The Ease-of-Use mod over at http://www.weidu.org has components that allows anyone to romance anyone, allows you to romance all npcs, and to say anything without breaking romance, as well as keeping people in the party from attacking each other, and leaving if rep gets too low/high.

The baldurdash fixpack allow half-orcs to romance Viccy.