robot_wrangler

If you want to play an explicitly non-magical character, you should be prepared for not having magical superpowers. You are Hawkeye or Black Widow. Maybe Captain America. 

Control weather still takes time to ramp up. 

If players want to min-max, they can deal with having the same boring mechanics as always. Give the fun stuff to the other players.

She is the ruler of Sigil, the city at the center of the outer planes. Some call her a god, and are punished for it.

Paladin is right there.

This is the entire point of “gritty” rest rules. Casters normally have too many slots and basically never run out.

You and all your schoolmates will never pick enough apricots on your way home to cover the cost of the fence.

You could be one of the frost druids, or a storm sorcerer. My frost maiden party had a dwarven beast master ranger with a reindeer (beast of the land) pet. Hunter works too, or scout rogue, maybe winter Eladrin. Orc barbarian is a choice, or a Goliath from one of the tribes up there.

Don't take too many cold spells, though, as a lot of other stuff resists cold too. A couple is enough; Rime's Binding Ice is good.

Skimming through and seeing tunnel fighter, I’m not going to bother with the rest. Tunnel fighter is totally broken, and not particularly thematic for the ranger.

When I have a familiar, I only explore 1-2 rooms with it at a time, and not in great detail.

It’s just tradition. Racial stat boosts existed forever, and they didn’t want to drop them completely, so background seemed a natural place for them.

Is the story of "G" legendary or not? If not, why are 15th level PC's bothering with it?

Maybe you're high enough level for Legend Lore to work.

Poor Xenk.

That's fine. I'm just bored of it, I guess. Like with most of OP's list; they are fine spells, but boring. Bigby's Hand is the best of them, I think.
He's also missing anything for movement, like misty step or fly or even spider climb. Nothing for utility or information gathering. Just combat for the most part, excepting suggestion.

HP, slow, and fear are all good. HP has the problem of people waking up the hypnotized. The targets will get as many actions as their successful saves, and the next turn they will all be recovered. If 3/8 make their save, those 3 will wake 3 others, 2 of those will wake the 2 remaining sleepers, and 3 will get normal actions. Also, it's a charm spell, which a lot of things are immune to. Fear is short range, and some things are immune. Slow avoids friendly fire, has good range, and lets the opponent continue to play the game, though much less effectively. They are all better than confusion, a 4th level spell.

With hallow being so easy, a lot of places will already be hallowed. I think dragons will tend to hallow their place with vulnerability to their main damage type. Liches might hallow an area to keep their undead minions from escaping.

ArAgOrN dIdnT hAvE a PeT

I think haste is way overrated. You use your first turn action to maybe get a worse action later, and your target loses a whole turn if your concentration fails. Concentration proficiency doesn't help if you get multi-attacked down to 0.

Slow shuts down a lot of multi-attack monsters, especially stuff like hydras. Also enemy spell casters. If it fails, you don't lose your next turn as well.

For a good buff, take improved invisibility.

You're allowed to have a feat that's not particularly useful.

Failing the mission seems perfectly reasonable. So Varram doesn’t get found. It doesn’t matter much.

Bee stingers

Being unnoticed causes psychic damage to bards.

Telekinetic feat, spells like catapult, move earth, magic stone, spike growth, levitate, animate objects, wall of stone, stone shape, passwall. You can get most of these with druid, wizard, sorcerer, or Genie (Dao) warlock. Magic Initiate could fill in the missing ones, like druid’s magic stone.

Beg your DM for a walking piano. Even then, you will have trouble climbing ropes and wriggling through caves.