You're not making any sense.  You darken your monitor, edit the image so it looks correct on the monitor, and then by virtue of the fact that you post it online, it looks "off" online?  On the same monitor?  That you just calibrated to that same image?  How could an image that you just adjusted to that same monitor look off just by virtue of the fact that you put it online?  You're viewing it online on the same monitor, right?  And even so, web browsers are not color managed.  The best you can do is convert to sRGB and hope it looks OK online.

Also what does "do not use the paper ICM" mean?  You are comparing selecting an ICC profile in Qimage to... what?  Letting the driver manage color?

It sounds to me like you are just confused about color management and maybe not using the right color management settings in the right places.  But that's just a guess.  Any monitor profiling puck depends on you manually setting brightness.  And even the ones that read "room illumination" and try to get you to set a monitor brightness almost always get it wrong.

You are mixing a lot of variables at once while trying to hone in on good output: trying different profiles/settings, putting images online and looking at them with a non-color-managed browser, etc.  Go back to that test image that you printed.  You said that comes out too dark.  Right away you have a problem in your printing procedures if that prints dark.  That's where you start (as others have pointed out).  Print that test image with the strawberries but print it on an OEM paper that is supported in the driver with OEM ink using a "Printer profile" that matches that printer and paper name (use "Suggest profiles" to find it).  If that comes out dark, either your printer is broken or you are expecting prints to be brighter than they should be.

Edit: Just to add/clarify, you print that test image per the paragraph above not because you are "testing" anything.  You print that as a baseline to which you refer.  Any printer running OEM ink will print that image perfectly if you use a paper that is listed in the driver and you select the manufacturer's ICC profile for that paper (the one that installed with the driver).  We do this so we can see what the image is supposed to look like.  Then we can match everything else to that print we are holding in our hand.  And that's why it is important that you print it with all OEM items: OEM paper, OEM (driver installed) ICC profile for that specific paper, OEM ink.  That's your baseline.  Without that baseline in your hand, you are just comparing to a whim/expectations which can be way off (even for the experienced).

Regards,
Mike

If the monitor is too bright the correct method is to set the monitor to factory settings, then use the X Rite to calibrate the monitor at a lower luminenence value. If it does still not match the print, re-calibrate again at an even lower setting. The value depends on room lighting, eyesight etc, I use 90 cd/m². and the colour will always be at the ICC standard.
You could also check that you are not double profiling which can lead to dark prints, and that you are using the correcr profile for the paper/printer combination.

Brian

First of all, THAT paper is not to be used with that printer. Says so on Canon website. Second, there is no driver setting for it, and there is no profile for it. It is very cheap paper not a Canon Pro paper. So I don't know where to go from here. Again, make sure you are not using the XPS driver.
I don't mean to sound rude or in any way insulting, but 50 sheets of the real Canon 4 x 6 ,is $12.31. .Would probably have saved a ton of ink, time, and stress.
Sorry, Fred

As far as the color and brightness of the print, yes.

If you have the driver set to Scaling, it will chop off a part of the image. (see screen snap) Set that to Normal See screen snap
Paper ? Canon Pro paper.... which one? Glossy N, Pro Matte, Pro Luster, Pro Semi gloss?
All different profiles. All different driver paper choices?
Are you using the regular Canon driver; not XPS driver??
Let's not discuss Light Room etc. Let's stick to getting Qimage set right and your driver set right and get a proper print.
Let's see your QU settings and your driver settings  please.
Fred

OK, let's try to simplify and get on the right track.
First of all, what paper are you using?  Second, since you have a Pro 100 printer, that came with profiles.
Third, lets take a piece of Canon paper and select the correct profile for that paper, and select it in QU where it says Printer profiles; see screen snap.
Now set the driver. Set the Quality to highest it will go,1 is the highest. Depends on what paper you selected.
Set Color matching to NONE/ see attached screen snaps. Paper type and size match too.
Make a print!!!
If we start this way, it will work.   
I realize you  might have some sophisticated paper that you profiled, or the manufacturer supplied a profile.
We will tackle that later after you make a perfect print, this way.
fred

It will always print close to the edge of the paper because the poster panels are intended to be cut right at the edge of the prints so there is no border on any sides.  That allows you to butt the adjoining edges together to create the least visible seams.

Regards,
Mike

Where are you setting Custom size?
In Qimage, see snaps below.
Fred

Great. I am  using a Pro 100 also.
Did you set the size in Custom size to LONG SIDE 47"?

Step 1 Select your printer setup (Semi gloss 19 x 13 Landscape)
Step 2 Open Custom size and set LONG SIDE to 47"
Step 3 Add pano image (Auto crop off)
Step 4 You should see as in my screen snap a full left to right pano image with little tag 3x1. That is telling you that we need 3 sheets of paper.
Step 5. Hover your pointer over the image. Size says, size, 47" x 12.68.
MINE SAYS that.   Yours will say 47" x the vertical pixel count. ratio.
Maybe you think that shrunk the print, but it is keeping the aspect ratio of the image.
If you need to fill the vertical better then you will need to shoot a set of vertical shots above the main shot.
In other words, Take your first shot. Now take a shot above the first. Now move to Shot two position. Take the shot and a second vertical.
I should get Terry on here. He takes panos all the time.
Fred

Hello, dw
Not much info above so I will guess and assume.
What Printer? Roll paper capability?  I assume not.
If you do have roll paper, Qimage will print the whole thing in Banner mode.
Assuming not, then Qimage will use POSTER mode. It will automatically enter poster mode once it sees a print order larger than the paper size.

I selected the largest sheet paper I have; A3+ or 13 x 19 in landscape mode on screen. Then I set Custom print size to Long side 47".
I add my pano, and Qimage sees the size issue and automatically makes 3 panels for the image to satisfy the 47" request.
See screen snap upper left. Very small text.... 3x1. Telling you it needs 3 sheets for the width only.
Hope this helps.
Fred