I am looking for the best realistic quality camera

The Nikon D800 is an incredible camera.  I have used it and love the photos.  That said, it is no where near three times as good as the D7000, but it is three times the price.  You would be paying a lot of money to 20 more mega pixels (more than twice as much as the D7000) which you will never actually see.  Viewing photos on you computer screen, those pixels will disappear because there aren't near enough pixels in a screen to render them all.  Same goes for a TV screen and even large print-outs.  You don't start seeing the 20 MP extra until you start making billboards with it, and then, it's only if you are standing in front of it rather than driving by it fifty yards away.  Simply put, you will never use 36 MP, so it's not worth tripling you money for.

Yes, there are other benefits of the Nikon D800 (like better low light performance), but the D7000 performs well enough for most professional photographers and definitely well enough  for an amateur.

The D800 is simply not three times as good as the D7000, nor even 50% better.  You will not need the benefits of it, nor will most other people.

1. It's not worth it for you. Probably. 

2. Get a D7000, the D800 is not something you need, just something we all want.

You will not be able to use the D800 effectively if you are not comfortable shooting in manual or even semi-manual modes (e.g. Aperture Priority). You need to move away from shooting fully automatic in scene modes. Don't feel inadequate about not being able to shoot manual, it's overrated and even many many top line pro's don't. You're camera does the maths and uses the in-camera meter, same as if you shot manual. If you have it, throw on auto-iso if you worry about slow shutter speeds. 

When you do upgrade, upgrade your lenses too. I recommend you get a fast prime (35mm f/1.8 DX or 50mm f/1.8) onto that list for crisp clean quality images that the other lenses won't achieve as they sacrificed that for variable focal lengths. That 50mm f/1.8 AF-D costs $100 or so, bargain, great for low light and good bokeh/subject isolation. Good contrast and... well... primes just give better pictures. 

3. Shooting a DX lens on a D800 causes the camera to shift to DX-mode. It turns itself into a DX camera. You get a 15MP image, not too different from the D7000. 

4. What? 4? But there's only 3 questions? Lastly, if you want to make photography a bigger part of your life, a deeper hobby, if you have the time and money, get the D800 and at least one decent zoom lens, e.g. 24-70mm f/2.8 AF-S and a 50mm prime and learn technicalities. It'll cost you nearly $5,000 but that's nothing if you have a passion. You can also be lazy and crop the hell out of the 36MP raw file and no one will ever know. You do shoot in raw, right? :D

Unless you are planning on becoming a Professional. The D7000 is more camera than you could ever need. It is a GREAT camera for almost everything.

The D800 is a serious camera that requires a lot of technical knowledge and is not as user friendly as the Pro-Sumer or Consumer bodies like the D7000.

I own the D7000, D300s, D90 and D80. I am getting a D800 but then I have more money than sense at times!  I was also a Military photographer for a few years and have schooling for it.

You can see a ton of wildlife images I shot with my D7000 here:

www.exclusivephotoworks.com

d7000 should satisfy you more than u expect for the current usage pattern

keep d800 or other fx cam under a target timeline of 4-5 years when u will have more experience to handle and manage the images better in camera and in dark room

not only an FX body would cost more + the lenses would cost more as well + u may need huge storage - which may restrict things

go for d7000 and few lens - climb the ladder step by step - all d best

I think you might be a prime candidate for the new D600 - which is only at rumour stage at the moment - but is likely to be only a little more than the D7000 - but a whole lot better.

Sadly you probably won't be able to buy one until the autumn - possibly late autumn?

It will be a 'entry level full frame'. Your DX lens will still be OK, but to benefit more you would need an FX lens. However, even the cheap 1.8D 50mm (at about £100) will perform really well on a FX camera.

And your 70-300mm will still work fine (I presume this is not a DX lens as well - you don't say it is)

Try Aperture priority to start off with, you set the aperture, camera does the rest. Then try shutter priority, you'll learn loads this way - and if you really need to be able to use the fully manual setting - but don't see this as an ultimate goal. It is not about using manual over above auto, it is about understanding why you are getting the photos you are getting. So try and see the difference between F2.8 and f16 - for instance in relation to depth of field and so on. 

I think it is wrong to think working in manual is somehow professional and using the auto modes not. Silly.