Actually as small as a 2x2 matrix of 14-bit values. See http://www.cambridgeincolour.com/tutorials/camera-sensors.htm

Each raw sensel of a 2x2 array value contributes to the color and brightness of the four RGB pixel values at its corners.

Because the Bayer array and the sharing of the information from each sensel, the image is less sharp (slightly smeared or about 1/2 as sharp) as for an sensor without a Bayer array. That's why an 18 MP Leica Monochrom is as sharp as a 36 MP D8xx and why a 19 MP Foveon sensor is inherently sharper.

The additional raw sensels of a 4x4, 6x6, etc., array around the target RGB pixel are used as a reference to improve noise suppression by removing the effect of hot, dead or otherwise inaccurate pixels. The do not otherwise improve the overall precision of the color or brightness.

As susual you are presenting information without comprehension.

A 2x2 matrix will resolve edge transitions more sharply than a 4x4, 6x6 or larger matrix. That's why the ultimate sharpness is achieved without any Bayer array at all, in effect, by a 1x1 matrix.

As for "more accurate" color, there really is no such thing. The color in an RGB image is the result of combining 50% green, with 25% red and 25% blue pixels by weighting their values to make the colors come out right. The first step is getting the numeric representation for each color to come out as close as possible to equal for a very dark, middle gray and very bright neutral (colorless) subject. Beyond that there is a lot of weighting, calculating and adjusting involved. The question as to whether they are accurate is somewhere between subjective and scientifically measured.

Five years from now you may find yourself coming to the following conclusions:

Raw is easier and faster to edit, requiring only modest skills.

JPEG is convenient, but results can vary widely, and they are harder to edit.

You can shoot Jpeg and get most of the tonal range you saw, if you are lucky, but you can be much more precise with raw, and you'll be able to take better advantage of your camera's full dynamic range.

Raw records more fine detail.

When you have to make broad adjustments, raw files are more "pliable."

An edited raw file is essentially incomplete - you still need a pixel editor to finish the majority of images.

In high contrast situations, settings that can produce an ok Jpeg will produce a similarly mediocre raw file. But properly exposing for the highlights, often resulting in darker looking images out of the camera, can produce stunningly beautiful images, that will always look better than the out of camera jpegs.

There is no real difference between an amateur and a pro with respect to image quality. Each is capable of both. The better distinction to make is between someone who takes his/her art seriously and a hack. Those who care and seek to make the best images they can will take the time to fully exploit the capabilites of their camera, and their images reflect the effort. This totally applies to both amateurs and pros alike.

The point of JPEG is to use the same sort of "PRE-processing" that it took to get great color slides. Careful use of an exposure/white balance target, plus menu settings that give your images precisely the look you want, are the steps that are equivalent to using an incident meter, a color temperature meter, color balancing filters over the lens, and good film choice...

It's a completely opposite mind set from working in raw. The goal is NOT to edit a JPEG. It's to use it as-is, or with minor adjustments. If your situation is such that you cannot trust your exposures, or you know you must do substantial post-processing for creative reasons, then raw capture makes the most sense.

Those of us who burned through countless bricks of slide film years ago had no trouble learning to work with JPEG capture. Many pro photographers who worked exclusively with color negative films prior to 2000 had serious trouble learning to make usable JPEGs.

I was a trainer at a school photography company from 2005 - 2012. I watched our lab customers grapple with JPEG digital capture and freak out! A lot of old-timers retired. One guy went into a manic depressive state and sold his business, rather than accept the fact that we threw all our film processors and optical printers into recycling heaps.

It all came down to a latitude change. Kodak Portra 160 had +2, -1.3 FULL stops, before things got wonky. JPEGs have +1/3, -2/3 stops of latitude before you can see noticeable quality degradation.

LABS fixed customer exposure errors when we printed from film and film scans. So photographers got lazy! But with JPEGs, we couldn't fix the kinds of errors they were used to making (never knew they were making!).

Raw is most similar to color negative film. The difference is that YOU perform part or all of the lab process. Labs generally don't process raw files. So the onus is on photographers: Get it right at the camera, or get it right at the computer. It's not a debate, it's a choice!

On the subject of keywords:
you can addd keywords when importing as described above. However, all the keywords you enter are applied to all the images you are importing. If you have a lot of images covering different subjects it's going to be hard to choose keywords that are appropriate to all the images. I find it easier to select a group of images with a common subject and apply the appropriate keywords to all of them on import. Then I select a group of photos with a different (but common to them) subject and import them with another set of keywords.

When you look at the images in grid view (press "g") the panel on the right will include a section "Keywording". Use the arrow to the right of that word to expand that panel. There will be a box in which you can type keywords. Keywords can include spaces. Keywords are separated by commas.

1600-1700 images? Are they all one subject or are you just letting images build up on your card until you have time to put them into LR? I think that would complicate the process. It would be easier to either send the images to your computer more frequently or change cards after you have finished with a particular subject. Another possibility is to try something like Downloader Pro. That program will download the files from the card to your computer (or external drive). You get a dialog with thumbnails of the images on the card and you get a panel on the left with dates from the EXIF data on all the image files. You can click on one date and the program will automatically select all the files taken on that date. Or you can select several dates. Or you can select individual photos from the thumbnails. In that way you can select all the photos with a given subject, then download them where you want them. I use folders named with the subject. For details see http://www.uglyhedgehog.com/user-page?upnum=1595

I'm not suggesting that Downloader Pro is the only way to go or even the best way to go. It's the way that works for me and I'm just offering it as an example to show how I organize my folder hierarchy. I believe that an organizational method outside of Lightroom is as important as an organizational method within Lightroom. Also, Downloader Pro has been around for a while so there are probably newer programs out there that would do the same thing.

I'm not very good at remembering dates so I don't generally organize or search for images by date. I search by subject. In fact, sometimes the only way I can find out when I shot a given subject is to look at the images in LR (I include the date in the file name).

As far as building up an immense list of files in your computer or on your external drive is concerned, the delete key is an essential tool. I'm pretty anal about keeping too many images. I have to force myself to delete stuff. I compromise sometimes. I delete a file of little value from the Lightroom catalog, but not the disk. That way it gets backed up, but it doesn't clutter up my LR catalog. In Lightroom you have two delete choices. (best done in grid view) Select a group of images youdon't really want. Hit the delete key. A dialog will come up asking if you want to delete the file from the disk or just remove it from the LR catalog but leave it on the drive.

I'm not sure if I answered your question or not. Feel free to ask me to clarify anything that I didn't.

PS: I'm a Windows guy. I have noted a few differences between Windows LR and Mac LR. I don't use Mac so I can't really troubleshoot in that case.