Feral Specific Questions:

What are the Hit and Expertise Caps for both Cat and Bear Forms?
Hit Rating reduces the chances for your attacks to miss. 32.79 Hit Rating reduces the chances for your attacks to miss by 1%. You need a total of 8% or 263 Hit Rating to Reach the Hit cap, after which no attack will miss. This is the amount required for both Bear and Cat forms.

Expertise reduces the chances your attacks will be dodged or parried (not to be confused with attacks that just miss). 8.2 Expertise Rating gives 1 Expertise. Each point of Expertise reduces the chances that attacks will be both Parried or Dodged by 0.25%
There are 2 caps for Expertise. These are known as the Soft Cap (or Dodge Cap) and the Hard Cap (or Parry Cap).
The Soft Cap is 214 Expertise Rating = 26 Expertise = 6.5%
The Hard Cap is 492 Expertise Rating = 60 Expertise = 15%

For Cat form is only required to reach the Soft Cap, this is because mobs cannot Parry from behind (where every dps should be), hence only eliminating their Dodge chance is all that is required.
For Bear form it is required as a minimum to reach the Soft Cap (more important than reaching the Hit Cap) and then to generally gather as much Expertise as is feasible while aiming for the Hard Cap.

What should my attack rotation be to give me the maximum DPS possible?
Unfortunately, unlike other classes Cat Druids don’t have a fixed attack rotation. They more have a list of priorities, which goes as follows:
Keep up Savage Roar
Keep up Rip. (5 combos)
Keep up Mangle
Keep up Fairie Fire
Keep up Rake

Use all additional energy on Shred (our best attack)
There are also a few additional options:
If you have another Feral Druid or an Arms Spec Warrior in the raid you can have them provide the Mangle Debuff for you thus giving you one less thing to worry about
Additionally, you may find yourself at times with all of the above running on the target with plenty left on there duration and back at 5 combo points. Then, and only then, you can use Ferocious Bite (as close to 35 energy as possible)

I want to be a Pure Tank (Main Tank), what sort of Gear/Gems/Enchants should I aim for?
First Priority is the Expertise Soft cap (6.5%), Followed by Hit Rating (up to 8%) After which getting as much Agility, Stamina and Armor as you can possibly manage.

How do I go about being the best Bear Tank I can be?
By making the Healers life as easy as possible and while maintaining as high a threat as possible so the DPS don’t die. (sounds simple huh?)
Don’t be afraid to use your defensive abilities often (Barkskin, Survival Instincts and Frenzied Regeneration)
For single target: Mangle/Maul spam, Lacerate in-between Mangle cool downs until you reach 5 stacks, then replace Lacerate with Swipe (yes even on single targets) and Lacerate only to refresh the stack.
For multi-mob: simply spam Swipe and Maul while switching targets frequently. It is advisable to use Mangle on the first mob in the Kill Order.

I want to be able to Tank (OT mostly) and DPS (good enough while not tanking) in one build how should I Gear/Gem/Enchant for this OT/DPS role?
Ideally you should have 2 sets of gear to fill this role. 1 set for tanking and 1 set for dps (as outlined above). If this is not possible (maybe your only just starting out), opt to collect a tanking set first, as it will perform quite well when you need to dps

What Glyphs should I be using for Tanking, Cat and Hybrid?
Tanking Major: Maul, Frenzied Regen, Barskin
Tanking Minor: Challenging Roar
Dps Major: Shred, Mangle, Berserc
Dps Minor: none
Hybrid Major: Shred, Berserc, Frenzied Regen
Hybrid Minor: Challenging Roar

A good 3rd option for Minor is the Glyph Unburdened Rebirth, so you never have to worry about having the mats for it