Is this homebrew Arcane School of Phantasm (Variant School of Illusion) balanced?

Question

Context: I have a player who is attracted to the "flavor" of being an illusionist, but finds the School of Illusion in the PHB to be rather lackluster, especially before 14th level.

Here is an alternative. Is it balanced, relative to most of the other Arcane Schools in published sources for 5th edition?

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Arcane Tradition: School of Phantasm

(Variant School of Illusion)

You practice the art of projecting your imagination out into the world with convincing apparitions, and have enhanced this ability in various respects.

Phantasmic Acumen. Beginning when you select this school at 2nd level, the gold and time you must spend to copy an Illusion spell is halved.

Multiple Minor Illusions. Beginning at 2nd level when you join this school, whenever you cast the minor illusion cantrip, its effect does not automatically end when you cast it again. Instead, you can have a number of simultaneous minor images equal to your proficiency bonus. If you already have that many active illusions, you choose which one ends upon a new casting.

Mage Hand Imagery. Beginning at 6th level, when you cast silent image while your mage hand is active, you can choose to conjoin the image to the mage hand, such that any spectral appearance of the mage hand is concealed by the image, and whatever the mage hand is carrying or manipulating appears to be carried or manipulated by the image. With an action, you can control both the image and the mage hand in a coordinated fashion.

Multi-Sensory Illusions. Beginning at 10th level, when you cast an illusion spell or cantrip, you can add a sound or an odor (or both) to it, if the spell does not already have it.

Potent Illusion. Starting at 14th level, your major image spell is so convincing that it can do damage. If the image is of a creature whose stat block includes a melee weapon attack, you can use an action to make an illusory version of that attack, using your melee spell attack bonus. On a hit, the amount of damage is one half of that shown in the stat block (rounded down) and is converted to psychic damage. There is no damage on a target that has succeeded on an ability check to see through the image, and each time a target takes damage from this feature, it attempts an Intelligence ability check to discern your illusion.

Answer 1

1. It's too specific - 3 out of 5 abilities are tied to very specific spells.
2. 'Potent Illusion' is a bit too complex and too specific - it covers only creating images of creatures. What about turning floor into lava? Creating an illusion of thunderbolt hitting enemy? Creating an illusion of harmfull spell hitting enemy? Also - there is no limit of what can be 'illusioned' into being, except that it should be something fitting into 20ft-cube, which, I suppose, can be used to summon something dealing serious damage (needs checking)
3. 'Multi-Sensory Illusion' - of all illusion spells, only about 5 can benefit from ability to add sound or smell to them, which makes it quite questionable feature to put it at 10th level.
4. 'Mage Hand Imagery' - while it's creative, it covers only two specific spells, which makes it not really worthy of 6th-level feature.

In general - it feels much less like a subclass for wizard and more like a variation of 'arcane trickster' with a limited number of spells, most of which are fixed.

So, with that in mind, I'd say that compared to other Arcane Schools, School of Phantasm feels underpowered balance-wise and prone to abuse. It doesn't add powerful abilities that can turn the tide battle of significantly change anything. It focuses only on few spells of the school, ignoring the rest (though I've said a lot about it already). But with those spells it leaves a lot for players to abuse. Especially, since some of those abilities have unclear wording, which leaves a lot for player's interpretation.