Warlock patron mix: The Radiant Dragon

[falsedot]

Hello!
I'm trying to come up with a dragon patron that's not too similar to what you'd get by being a dragonborn or a sorcerer with a draconic bloodline. More of a "some tricks a dragon taught you" feeling.
Regarding the radiant part of the dragon, it's mostly a thematic choice that echoes the celestial warlock (and provides a back-up revivify)
Bit unsure about the coherence and balance though, so any feedback would be appreciated!

Expanded Spell List
1st burning hands, command
2nd flaming sphere, pyrotechnics
3rd daylight, revivify
4th wall of fire, charm monster
5th dawn, wall of light
not sure if giving firebolt and sacred flame would be a good idea

1: Draconic presence (same as fey presence)
You've adopted the mannerisms of your patron.
Once per short/long rest: As an action, you can cause each creature in a 10f cube to make a WIS save or be charmed or frightened by you.

6: Dragon's Luck (same as dark one's own luck)
A bit of your patron's luck rubs off to you.
Once per short/long rest: Add a d10 to an ability check/saving throw.

10: Draconic Acclimatization
You've got used to your patron's temper tantrums.
You gain fire resistance and advantage on saving throws against being frightened.

14: Dragon's Hoard
Your patron trusts you enough to grant you access to the hoard - or perhaps they think you are part of the hoard. You are allowed to pick a rare item from it - but a stern warning not to be greedy is issued.

The hoard contains rare items around the power level of Wings of Flying to Winged Boots* (so 5k-8k in the Sane Magic Item Prices tables). While the final hoard depends on the DM, it would be expected to have a Wand of the War Mage +2, a variety of Ioun stones, a +2 Weapon, a Dragon Scale Mail, or the Dragon Eye described bellow. This magic item should not be included in your expected magic items per level.

* I'm basing this on the Dragon Wings from the sorcerer

Dragon Eye (Attunement, Warlock) (basically a rod of the pact keeper minus the wand of the war mage)
This amulet was made from the petrified eye of a dragon. When worn, you can speak the name of the dragon to regain 1 warlock spell slot.
You can’t use it again until you finish a long rest. You believe that the eye blinked once or twice; and you felt your patron's presence through it.


Invocations
Dragonscale armor
While cleaning your master lair you've managed to save enough scales to make a lightweight dragonscale armor. Your AC becomes 13+DEX.

Radiant conduit
When casting a spell that deals fire or radiant damage add your Charisma modifier against one target of your choice.
OR only for radiant damage but to all targets?