Thanks [MENTION=20323]Quickleaf[/MENTION]. Appreciate it.
I should clear up, and if it's reading this way, I really need to clarify the writing, but the "individual creatures" of the Favored quarry are not, specific individuals. That is, you don't choose "The Orc named Grod."
The PHB allows you to pick creature categories (Beasts, Elementals, Giants, Dragons, etc...) or two Humanoids.
I meant, following your 1st level pick, you can choose single types creatures...since you can not choose the whole category.
In other words: We have two rangers, say.
One starts with Giants. She wants to go out hunting Giant types and take down the evil Fire Giant King. Great. Her bonuses from Favored Quarry apply to ANYwhere he encounters a monster of the "Giant" type: so, actual giants, ogres, trolls (?I think) and anything else listed in the Monster Manual with/as/of the "giant" category (not "giant animals", obviously).
Ranger two, instead, goes a bit more traditional, elf ranger with the whole "orcs slew my village/family/parents, wah wah, bitter jaded loner guy." He chooses, instead of one of the categories listed, to take Orcs &...what do orcs generally fight with...let's go with Goblins. Very classic D&D elfy kinda enemies to have.
When it comes time to select new Quarry, Ranger 1 is finding that at 1st-3rd level, she's not running into very many giant-types. She did put the serious smackdown on that ogre, that one time. BUT the party is running into goblins and orcs left and right. The other party ranger is having a ball. So, for her "individual creature" at level 4, she picks "Orcs."
Several levels later, a bit more has happened and they have had multiple forays into an arctic tundra to repeatedly raid on the Frost giant's ice-fort. There is a pack of white dragons that hunts the territory and, whether they are working with the giants or not, they have become a recurring and consistent threat and nuisance when trying to get to and fro the frost giants. So, for her 7th level "individual creature", she chooses "WHITE dragons".
...You see? Since she can not take the whole category of "[All/Any] Dragons", she can choose the "individual creature",
White Dragons...not a singular, one, white dragon...all white dragons.
For the Warden, I am thinking of actually trimming them way back down to an Eldritch Knight level of casting...and ggranting them access to the druid cantrips. We'll see.
I need to do some reworking, of course. This whole Favored Enemy business seems to stick in a lot of craws...I just don't get it.
OH! As for the Nature's Ward, that is a straight out of the PHB Druid's ability. I thought the same thing, "What elementals cast charms or fear"...but I suppose genie's might cast spells...if they keep nereid's water elemental creatures (instead of properly switching them to fae, as a subset of nymphs), they could charm. Sylphs, air elementals...I don't recall their spell use...but I don't remember a charm.
I don't know. But, so, that's not any homebrew/setting specificity going on, it's a direct quote from the PHB druid ability of the same name.
Nice to know someone caught the nod to magic-user spells in the guardian too.

Thanks.