It's impossible to provide an adequate simulation of everything that is theoretically possible because that's infinite. If there's specific things a player wants then it can be homebrewed and would need to be fun and balanced against other features. Creating a trap options for PCs just because...
I would consider plagiarizing some stuff from the FR the Order of the Dark Moon. These were Monk/Sorcerers hybrids using the shadow weave that were the spies/assassins for Shar. Thematically they make for a solid mage hunters.
In terms of stat blocks start with Martial Arts Adept from MPMotM...
Yes if you want your PC to retire from adventuring and spend the next 5 years training sure go ahead, in the meantime roll up a new character and let's continue the current campaign we are in. Or find or create a homebrew class/subclass/feat for whatever it is and if it's balanced it will be...
The simplest in world explanation for why NPCs have a different set of skills/features/rules from PCs is due to the nature of experience. Gaining experience by fighting monsters provides different "lessons learned" then training/study/etc... so it makes sense that the abilities would be...
A PC can take PAM and get 3 attacks with a spear at level 5, so I'm not sure it should be all that surprising when an NPC does something similar. In the end the NPC statblock is simply a streamlined version of things. So sure maybe the 3rd attack should be a BA with a marginal damage difference...
If you want a house rule to explain the HP bloat tell your PCs they can take the Tough feat multiple times and have it stack. It's doubtful the players would ever take you up on it, and won't break the game even if they did, but it does provide that in game mechanical a rational for how they got...
Haven't read the whole thread but in an argument that boils down to individually controllable summons vs a single swarm type of summon perhaps a best of both worlds approach would be to allow individually controllable summons but turn around and give the Necromancer the ability to create a swarm...
Obviously you don't, instead you use that 2nd level spell slot on Enhance Ability or Misty Step or See Invisibility.
The idea is that as you level up and get better spells (And your cantrips get better) what you use your low level slots for should change and play a more supporting role, or...
Never had that problem, the type of spells you prepare and use might change, but stuff like Shield remain useful forever, Silvery Barbs is something that you'll want to cast often no matter the tier of play. Hell just dump all your low level slots at the start of the day on something like Gift...
As a note one possible answer to low level control spells might be to follow the design philosophy of something like the 2014 Sleep spell. It's great at low level but runs out of steam pretty fast as you level up forcing you to start using higher level spells.
Doesn't even have to be HP based...
Although I agree more monster should be virtually immune to some low level magic I'm not sure I buy the idea that it should be common for bosses.
The problem with low level control spells making higher tier bosses too easy shouldn't be "fixed" by also nerfing spells like Scorching Ray.
Haven't read the whole thread but I would note that given the dragon did KO a PC the fight so even if unsatisfying it did meet the "deadly" definition. And had the dragon gone after the Wizard instead of the Monk dropping them instead, well Suggestion is a concentration spell so the minion can...