Okay, so I'll start easy...
Blacksword: It seems to have three properties, besides "+3 magic weapon".
1) "cannot be put away until it draws blood"
The first one I'm not sure should affect pricing. Because it seems rather easy to avoid, having this as flavor only might be okay. The actual damage would of course be rewritten as "if you try to sheathe the weapon before it has drawn blood, it makes a attack +19 vs Fort against you for 1d12+3 damage. If the attack hits you fail to sheathe it and you will have to try again."
Its attack bonus needs to be set: considering the sword to be a "monster", the Soldier Role has an attack of Level + 5 vs non-AC defenses. The base level for a +3 weapon would be 11, though the healing powers ups this considerably. The damage (your 1d12 plus +3) isn't out of line for such a monster either (it falls into the "low" category of the DMGs suggestions).
Damage should, I think, feature its enchantment bonus. I have added that in above.
2) "cast cure critical wounds"
As I understand it, a
very desirable power for a 4E item to have. Let's say you have a Daily that returns hp equal to what a Healing Surge would have given you plus three (for the +3 enchantment). That would make it at least a level 14 weapon.
3) "save or shift one alignment step"
As long as you don't reduce the price for this curse, I guess there's not much to add. I'd make it an attack vs Will rather than a 4E save though. I'd lower +19, though, to perhaps +15.
If you retain CSW or the alignment shifts the weapon really needs to become a minor artefact, and thus pricing becomes irrelevant (it can't be made). In that case only a suggested level range remains to be set, and that's easy: "mid-paragon tier".
If you skip 3) and reduce 2) to something along the lines of a "free Healing Surge", it could work as a level 14 weapon (and indeed, this is how I arrived at the +19 attack bonus).
Generally you'll see that items (even artifacts) have subdued powers. This is in line with 4E, because it makes adventurers less reliant on items. At first, you'll be disappointed because your items won't (and shouldn't) be as cool, but hopefully you'll come to see this nerfing as an advantage.
