While Spellsword does indeed give you the martial and exotic proficiency feats, it still doesn't allow one to take Weapon Focus for weapons other than those of Simple Proficiency. Is there any way around this?
I hope not!
There is no way around it except actually taking the feat yourself.
This is no bug.
Not a bug, feats granted by perks (i will assume) are like bonus feats from items and so won't count towards prerequisites.