I've always liked the concept of the Druid and the Ranger but I hate some of the mechanics they use in this game.
Ranger:
I don't like the Favored Enemy ability of the Ranger. It's too circumstantial. If the DM doesn't throw your Favored Enemy at you, you never get to use your bonus.
One proposal I've seen to get around the circumstantial factor was allow the Ranger to reassign his favored enemy bonuses after he fights a new creature.
For example, Torak (Ranger 5) currently has Favored enemy of Orc +1 and Dwarf +2. He encounters and fights an Ogre. After that fight he may choose to reassign one of his favored enemy bonuses to Ogre. He decides to reassign his +2 versus Dwarf to Ogre. The next time he encounters an Ogre he gets the +2 modifier but he no longer receives the bonus against Dwarves.
With this method, the Ranger is not stuck with his choice at early levels when later in life he may be fighting mostly Demons and has no bonuses.
This doesn't help with the other problem though.
Also it doesn't make any sense to have a Favored Enemy based on race if there are many different cultures within the race. For example, how would one get a bonus against all Humans if Humans come from 50 different cultures which all have their own nuances?
What would be a good substitution for Favored Enemy? Feats?
If you remove Favored Enemy then you have to figure out what to do with Quarry, Improved Quarry, and Master Hunter.
I can see making Quarry and Improved Quarry work against any creature without it impacting the game too much.
Probably the same with Master Hunter. Make it usable against any enemy but only usable 5 times per day and each use must be against a different enemy.
Any ideas on this one that still keep it balanced?
"Roll a Fighter" is not a good solution because they are not the same. Rangers only get Light armor, they get more skill points, favored terrain, hunter's bond, woodland stride...
Druid:
I don't like the Wild shape ability. I'd like to see a nature-oriented spell caster that doesn't have shape changing built into the character. Shape changing can be accomplished with spells.
Would I be better off with a Sorcerer variant that uses the druid spell list and a modified Blood Line?
Ranger:
There are some ranger option in APG that let you replace the Favored Enemy option with other chooses.
Druid:
You could just decide no to use the druid shape changing ability. After all, OD&D and 1st Ed D&D did not have Wildshape ability, but there spell list was also the same as what is listed in Pathfinder... but Pathfinder has more spell options now.