Alright. I took a look. Overall it's not the most broken of archetypes I've seen floating around, and is admittedly cool thenatically. Here are a few comments I have...
1) The extra spells learned are a BIG no. I wish sorcerers all got bonus spells like this. However, the game devs have gone on record stating that this is the one thing you should *not* do when making stuff for the sercerer. You might, however be fine adding some or all of them to the list of spell list you can pick from (pending DM approval). As for the spells themselves, I'll cover them in a bit.
2) Shield of Shadows, while fine as written, is perhaps a bit odd mechanically speaking. The way it's written feels very "3.5" in phrasing and system complexity (it's a bit odd for it to use a sorcery point AND have a max uses per long rest). I also suspect the person who wrote this may have chosen cover rather than the advantage/disadvantage mechanic to sneakily allow you to stack this ability with other mechanics that do allow advantage/disadvantage, and it creates a bit of a "stacking buffs" syndrome that this edition tries to avoid. That said, rather than just shaking sticks accusingly, I shall instead point out that some of the oddity that using cover creates from this ability.
It's design intention seems to be so that you are harder to hit in the shadows, and while the cover mechanic (a +2 or +5 bonus to ac/saves) does this, it also creates some unintended side effects such as allowing the sorcerer to hide (cover can be used to break line of sight). While I've no issue with a shadow themed sorcerer being "sneaky" and letting them hide easily, I would not let them do it from a reaction based ability (it lasts until their turn), and there are are number of other ways they could do it already (invisibility, skulker feat, casting darkness, etc.). Instead, I suggest making the ability based off of the advantage/disadvantage system. I would rule it in my game as letting the player take the "dodge action" as a bonus action when they are in dim light or darkness, and I would let them do it as much as they want, rather than the limit per short rest. It accomplishes similar goals. If the DM still wants you to have as sorcery point option, I'd let it be to spend a sorcery point to use your reaction to take half damage, possibly from anything except radiant damage.
Spells:
Shadow Spray should be 1st level spell. It's worse than web, a similar spell but the same level. Personally I'd make it 1st level, the same radius, and have the effects lower the lighting in that area by 1 step. This is similar to the level 6 ability thematicslly, and doesn't make Web useless. I also can't for the life of me figure out why they didn't call *this* spell shadow net. It's a spell that retains in am area. Typo perhaps?
Net of Shadows is too strong for a first level, and again brings up the wonderful mechanic of cover. Sure it makes them hard to hit from melee, bit conveniently has no cover to ranged attacks even though cover was a mechanic specifically designed to keep ranged attacks in line. *rolls eyes* If you DM wants this spell, make the following changes: a) make it 3rd level b) make it restrain targets instead of cover c) make it blind them or create a 5ft radius of darkness. The spell needs to not make Web or Blindness/Deafness obselete spells. Personally I like the 5ft darkness bubbles option.
Shadow Well. No. Just no. I LOVE the idea of this spell, but it is the same as the spell Banish (a 5th level spell), with 1d4 extra rounds of fear tacked on after a second will save (an odd thing in 5th)...as an 4th level spell. No. My suggestions for this spell are to make to remove the second will save and have them automatically feared for the 1d4 rounds (give and save at the emd of each of their turns to end the effect). Also, do one of two things, either make the spell 6th level, or reduce the initial time in Shadowfell to 1 round. The latter option still may need to be a 5th level spell, subject to your DM'S opinion.
Hope it helps. It's a fun archetype conceptually.
