Just a few cosntructive comments
Sense Emotion-Do consider changing it back to +10, if only because it gives bards a chance to fail a Sense Motive check vs. a good liar even with it on. Also change it to enhancement bonus b/c it currently stacks with most items. Otherwise, I'd keep it insight but make it only +5. Bards do after all have Sense Motive as a class skill anyways.
Silent Casting is very potentially unbalanced. Take for example the cost difference between a wand of fireball (5th caster level) and a wand of fireball (10th caster level), a wizard who uses Silent Casting a lot saves money and gains a whole lot more powerful fireballs per day. I would just take out that mention about raising the caster level of the item, or changing it to a fixed amount such as +X (where X = the level of increase the metamagic feat would be).
Leaf Shield-Seems vastly overpowered for its level comparing it to Shield of Faith, which gives +1 deflection mod/3 caster levels, I would just change the deflection bonus to +1/4 levels and consider giving them a penalty to saves vs. fire spells. Also, what kind of an attack does the magic missile wielder make on the bearer of the shield? Normal ranged attack, modified by Dex? This is almost as good as negating the missile outright with a Shield spell because most casters have poor attack bonuses. I'd either allow them to add their int to the attack roll (annoying as it requires more rules) or make it a ranged touch attack (giving a leaf shield wearer about a 50% chance of evading).
Blessing of Leeches-Cost heavily outweighs benefits. Permanent Con Damage is *nasty*, it can't be healed even in minute amounts til level 5 as a cleric, and even then by 1 point at a time with lesser rest. if I remember correctly. I would definately change this to Temp Con damage (heal 1-2 of that per day depending on how much you rest) and it would still be a bit much-Reasoning: you lose 1 hp/level every time your con goes down from even to odd. In addition for changing the type of Con damage I would make a clarification saying that the caster does not lose Hp from con loss due to this spell for teh duration. Another option would be to keep it perm con damage, but make it damage the caster once every minute, but always at least 1.
Anyways, don't get me wrong, I'm enjoying these spells and I can't wait for Art of Magic to come out.