Filters on a Linhof Technikardan 45, compendium?

Hi,
after a long evaluation period, a bought a Linhof Technikardan 45, which is now on the way to me. I will use it for landscape and architectural photography. Lenses will cover 47mm to 180 for now and will be used with an 6x9 roll film back, 4x5 only for really wide shots. The decission is based mainly on the hybrid workflow I use and an old Imacon Photo SCSI scanner I own, which can scan up to 6x17 without stitching. 4x5 will have to be scanned as two stripes and stiched later on, what I want to avoid. And sadly I do not have the time and space for an LF darkroom.

Up to now I use digital APS-C and full frame cameras, as well medium format 6x6 in black and white exclusive (up to now). As my main topic in the moment are long time exposures, I make use of ND filters on regular basis. Because of the prices, of proper filters, I went for the really cheap path and bought chinese Cokin reproductions, which had been perfectly ok on black and white film, as color casts had been no problem there. But as I started to use them on my digital cameras, I expirienced ugly red shifts in my pictures. The more filters I stack, the uglier. (I read about the behavior like an IR filter, when you stack ND filters, but that's another story)

As I want to go for propper stuff, for my LF pictures and want to shoot color (provia for now) as well, the color shift is not welcome anymore. So I thought to go for Hitech, Lee or Singh Rays. As they are not really cheap, I do not want to go into a wrong direction, and hope to get either confirmation or hints, when I am on a wrong path.

First, my filter set I plan to use:

Circular Polarizer (should work on digital as well)
square 4x4 ND filters in stops 2, 6, 10 (the Singh Ray 15 stop would be really great, but...) or something similar.
rectangular 4x6 grad ND filter 3 stops. (easier to brighten up after scanning, than to recover burned highlights. Scanner not the newest and has not the largest dynamic range.)
regtangular reverse grad ? stops.

If I shoot black and white, an red, orange or blue filter will be added maybe as well, but later. In the beginning I will use the cheap Cokin copies. They are used to enhance or decrease contrast of clouds, as it can not be done later anymore.

Now to my concerns:

Will a 4x4 (100x100mm) be large enough for the Super Angulon 47 XL on 4x5 even with shifts? (I do not have a center filter up to now, so it's pretty close to the lense. But this may change maybe.)
All my other cameras, do not have tilt or shift, so normal lens hoods did a good job. But as I plan to use shift a lot (not much expirience in LF up to now) I am afraid, a lens hood will darken the image.
If my last concern is valid, I will need a compendium. I do not know, how large the compendium for the 4x5 technikardan is, but I am afraid it will not be large enough to enfold(?) the lens with the filters, especial the 4x6 grad filters moved to one extreme. (At least I assume, it makes sense to pull the compendium in front of the filters, to avoid stray light. Similar a lens hood is used. But no expirience with that up to now.)

One last question: Is it possible to mount the filters on the compendium, or is it common to mount them on the lens with the holders from the filter producers, like one will do it with 35mm and medium format cameras? Hand holding is not an option for long time exposures.

I hope somebody with a similar setup can give some comment. :)
After dreaming about an large format setup, I am really eager to take my first shots and hardly can await it to be delivered...

Thanks in advance!
Andreas