After a discussion on the Keen weapon property I noticed that the basic effect of Keen exists as a weapon property, feat, and spell. This got me thinking of other things like that and wanted to ask for opinions about the possibilities of other effects crossing over to be a feat, spell or magic property.
What feats do you think should be available as a spell or magic item? Same questions for spells and item.
I think the biggest and most obvious for me is Amulet of Mighty Fist. It seems too nessesary to be an item, and I think the argument against enchanted brass knuckles applies to AoMF so really it should be a feat.
For some reason I think Vital Strike's effect would be more at home as a weapon enhancement property. There are few ways to really represent the oversized sword mechanically without messing up your character and really vital strike is unappealing because of it being its own action.
The oversized sword is best represented with the impact property. Vital Strike works very well with that, and even better when the wielder is enlarged. Of course, if you can reliably full-attack, and if your iteratives reliably land, it's less appealing.
Spells that should be feats.... Can't think of any off the top of my head. The closest I can come up with is some cinematic stuff, like burst of speed.