You got me. Leica doesn't bother to provide a RAW converter.

Where did I say cross polarization causes vignetting?

Stacking any type of filters can interfere with light entering at the edges of the lens. That is why filter venders offer low profile neutral density filters. I've never seen a low profile polarizing filter.

Southern Utah is certainly rich in opportunities for grand landscape photos. I go there at least once every year.

Great in theory, but not in practice. When you stack filters, you increase the likelihood of vignetting the corners of the recorded image. Any color cast will be multiplied by 2. I have seen several reviews of variable neutral density filters that rely on polarization such as you suggest. You can search for them yourself. You will find that variable neutral density filters generally produce poor results compared to the alternatives.

Each camera manufacturer (OEM) provides a free editor. OEM editors are optimized to convert RAW files and process RAW and JPEG files created by that OEM's cameras.

The card size I use depends:
1. Am I using my 20Mp camera or my 60Mp camera
2. Is my drive mode single AF or continuous, and, if continuous, how many frame per second and for how long bursts
3. Am I shooting in high resolution mode
4. Have I selected uncompressed or compressed files and full resolution or reduced resolution file size
5. Am I shooting RAW only, JPEG only, or RAW plus JPEG
6. Am I saving the images to both memory cards at the same time for backup or to only one card at a time

Your Canon R6 is a 20Mp camera. The fact that it is a full frame camera is not relevant. It is the number of megapixels the sensor contains that is relevant. You appear to be mostly a landscape photographer with a relatively low megapixel sensor camera. Your card size requirements are minimal.

If I am using my 50Mp Sony A1 in 20 fps continuous mode to shoot uncompressed images of birds in flight in a target rich environment, I assure you that a 32GB memory card is insufficient. It would only hold 250 RAW uncompressed images and would fill up after about 12 one-second bursts (only 10 if I am shooting RAW plus JPEG.

I normally don't need a camera bag; just a neck strap and pockets. If I am going to be hiking several miles or over difficult terrain, I will carry my gear in a shoulder bag for comfort and/or extra protection. If I am going on a several day long workshop out of town, I will use a small backpack that I can carry onto the aircraft and take an extra camera body. (I can charge my batteries in camera at night using a USB cable.)

For landscapes I carry the OM Systems OM-1 with the 12-100mm f/4 lens.
For wildlife I carry the OM-1 with the 150-400mm f/4.5 lens and a monopod.
For portraits and street photography I carry the OM-1 with the 12-40mm f/2.8 lens.
In my pockets I carry: Rocket blower, lens wipes, lens cloth, and either a 1.4x teleconverter or a small wide-angle lens (for wildlife or landscapes respectively).

I have never needed to carry extra batteries or memory cards (my battery charge seldom drops below 50%). Normally, I don't need a tripod or monopod because of the high quality OM-1 image stabilization.

While I can shoot handheld at 300-1,000mm full frame equivalent focal lengths in good light, the monopod ups my keeper rate when I am shooting in poor light or at the full frame equivalent of 1,400mm.

Be aware that you will likely get recommendations for the "best" available equipment currently, or soon to be, available. But you should consider:

High quality mirrorless cameras are not significantly lighter than equivalent format DSLRs; lenses for mirrorless cameras are not significantly lighter than lenses for equivalent format DSLR lenses. If you want lighter gear, you should consider crop sensor cameras such as Fuji, OM Systems, and Lumix. Another way to save weight is to buy non-pro lenses. Crop sensor lenses also have narrower fields of view for the same aperture (A 12-100mm OM System lens has the equivalent field of view of of a full frame 24-200mm lens). Crop sensor cameras and lenses will be less expensive. Most of the full frame flageship cameras such as the Nikon Z8, Canon R7, and Sony A1 will not provide significantly better image quality. You can find professional photographers that use crop sensor cameras, full frame cameras, or medium frame cameras. However, many tests show that most people cannot identify which camera (full frame or crop sensor) produced which large prints of the same subject; even on close inspection; even without the application of AI noise reduction and image size scaling--which make sensor size essentially irrelevant.

I'm not disparaging full frame and medium frame gear, I just think they aren't necessary for non-professional and most professional photographers. And it has cost me many tens of thousands of dollars to prove this to myself.

Crop: Yes. Your crop: No. (Flowers don't need breathing room--they don't breath.)

Looks like it is too late to purchase a Sony camera. Sony camera orders from Catholics spiked yesterday on news that the Pope uses Sony cameras. Sony cameras at camera stores are now backordered.

I think all photographers, from the mid 1800s to today, do the same thing: capture and process an image to create their vision of the composition, using whatever tools are available. When the tools evolve, so does the process.

1. Some electrical vehicle manufacturers (GM, Hyundai) have had more problems with battery fires than others (Tesla).
2. Overall, the number of vehicle fires per 100,000 vehicles is higher for internal combustion engine vehicles than for battery electric vehicles. But EV fires are always greatly publicized while other vehicle fires rarely are.
3. While Sony had a well publicized problem with Li Ion batteries in the mid-2000s, laptop and camera battery fires are very rare and are usually the result of damaged batteries.
4. Currently, electrical vehicle, laptop and camera manufacturers include protective circuits to prevent overcharging and over-discharging, more robust battery casings, and advanced battery chemistries.

The best camera is the one you most enjoy shooting with.

You don't need and shouldn't use those filters with a digital camera. They will cause a color cast that you will need to remove in post processing.