The TOEE set is crafted armor + crafted weapon. If you craft one of each you get +20 stacking bonus to your universal spellpower. The armor has lesser displacement + 150% fortification and the weapons have 156 spellpower (acid, fire, cold or electric), 6 spell pen and 23% lore matching the selected element.
The set is nice for great old one or fiend since it's slightly better than thunderforged for the spellpower, percentage and can be synchronized with energy burst. You can also apply +2-4 mythic bonus to each piece. For the mythic upgrade, the armor is prr/mrr and the weapon is more universal spellpower.
So it can give you up to 24 more light spelpower, but it's not critical. It's just an option since your docent is undecided.
http://ddowiki.com/page/ToEE_Crafting
The new docent gives you 12 universal spellpower (10 insightful + 4 int) and 0-4 prr/mrr depending on the mythic tier, so it's also not a bad choice if not using TOEE set or thunderforged:
http://ddowiki.com/page/Item:Epic_Docent_of_Insight
As for saves, yes the saves from paladin levels will absolutely make a difference, but not everywhere. In what goes up the end boss has flesh to stone and the divines before that have stuns. The stuns you can eliminate by swapping on epic chord of reprisals. If you go into divine crusader just for what goes up the boss can't turn you to stone if you choose the tier 5 option that makes you immune to petrification. You lose some dps ,but you still have options.
There are a few places (GOP for example) where you can get one shot by disintegrate. That would only happen on a 1 with paladin levels so odds are low you would get the big champion disintegrate crit and roll a 1 one at same time. On a 20 warlock if the champion lich crits you are basically dead unless you roll a 20.
For will saves you are fine with force of personality. For reflex you are basically fine because you have high MRR and are immune to knockdown. for fortification saves, you have to worry about sonic stuns (negated by epic chord of reprisals), pertrification (can be worked around by going into divine crusader and giving up a little dps for those quests) and disintegrates (I've only been one shot in GOP and TOEE).
In the newest 2 chains saves have not been a big issue for me. I've been hit by some big rakasha disintegrates, but never one-shotted. My feeling is I am willing to take a few more deaths in some content to be more powerful everywhere else, but others value never dying more.