A few points i though of
Favored Enemy
One way to improve the Favored Enemy class feature would be to include more foes in the one choice, based on type
For example
Favored Enemy : Humanoids
Nice and simple, all humanoids have similar weak points.
I have never seen the point in splitting elves and orcs for example, hearts are in the same place, strikes to the neck, groin and head will drop any humanoid, not just orcs.
To extand from this idea why not include the potion to specialize in a subtype.
So if a current charcater has Favoured Enemy : Goblins, you would give them, Favored Enemy : Humanoids, Deadly Foe : Goblinoids
Fovered Enemy, as is
Deadly Foe, +1 crit range, +2 attack rolls
Something along these lines makes it nice and backwards complatible, easy and fun to use.
Animal Compainion
Advance the Animal at the same rate as a druids -3 (similar to the plaidins reduced turning)
The other option (the one i prefer) is to count them as a Familiar (giving a skill bonus, and so forth), with the animal providing an aid another roll for attacks and/or CMB and a damage bonus if sucessful
Example
Animal Skill Aid Another Damage
Wolf +2 Listen Attack / Trip Atempts d4
Eagle +2 Perception Attack / AC d4
Snake +2 (Hide) Attack / Grapple poison
Ferret +2 Escape Art. Attack / Disarm 1
Ranger Combat Styles
Increase the number of Styles to include, two weapon fighting, two handed fighting, polearm fighting, single weapon fighting, ranged fighting and magic
If you select magic you gain spell like ablities
All the others give you a bonus feat
Next time you gain Ranger Comabt styles you may pick the same style to get increased abilities or gain the base abilities of a new style
Sorry this got a little long winded
Let me know what you think