There's sooooo much here.
Firstly, let me start off by saying I very much doubt I am an "effective" player.
But I wanted to answer your questions with another question, before offering my own pitiful advice.
What nations are you thinking of, specifically? Pretender choice/Magic paths are chosen within the framework of a national identity.
Any spells and items which protect your pretender from either picking up afflictions or being hit at all are good - Lucky Coin, Pendant of Luck, Body Ethereal, Protection, Mistform, etc. Regeneration and reinvigoration items are also quite helpful.
In general, if I'm trying to build an SC I go whole hog - I like to be able to send the pretender in by him- or herself.
For solo SCs, I really like the Wyrm with Astral 5 (casting Astral Shield, Astral Weapon, and Body Ethereal on himself before the enemy gets there), the Nataraja (with some Ice Swords and a Lucky Coin), and the Earth Mother. The Vampire Queen is outstanding, too, because of all her great innate abilities...so you can spend your forging time on other items for her.
But as I said, I don't know if I would consider myself good. I win more than I lose against the AI, but that isn't saying much.
EDIT: Oh, the Shedu and the White Bull make really good solo SCs, too.
[ March 25, 2004, 22:06: Message edited by: fahdiz ]