Rich - YES that WOULD be useful
Now, I'm famed for being patient with neww guys (lol) so I'm gonna look at these with an open mind and answer
Of course NO new suggestions will reach us by Patch four or five, DBS have their work cut out as it is
1) MAKE TEXT string, text number:
Admittedly I would actually use this, as maniupulating strings as objects could be useful. However you can already do this by obviously just loading a picture of text as a sprite or image. If you need a variable string rather than a premade picture, you could make the text generate in the program, then render it to a bitmap, crop that by determining the length of a string and then turn that into a sprite or image.

Long way round tho, your command would be quicker

I am skeptical how much use a z axis would be for text tho, so maybe a command to render text as a sprite would be better than an object, for ease of making moving HUDs etc.
2) COLOR TEXT colour value:
You can already do this, just set the Ink colour b4 making text
3) SET TEXT 3D text number, parameters:
Um, I guess most people would prefer to use a 3d package to get the 3d text exactly how they want. However a command to take a 2d image and extend its y axis would certainly have uses - although again most 3d paackages will do this with a small ammount of fiddling around
4) SET VOLUMETRIC FOG parameters:
Yes I can see where you are going with that. However personally I think the fog should only really be used for far away pop-up softening, and actuall weather/haze effects should be made by the users own enginuity
5) SET VOLUMETRIC PARTICLES particles number, parameters:
As above. Altho I can see more practical uses for this
6) TEXTURE BACKDROP:
Well I'm always annoyed when any fuction I use is taken away... but basically this was a very inflexible command anyway, due to the wallpaper style effect and lack of options for it - You're much better off using a textured plain, or if you must be 100% 2d, a large sprite or pasted image. Simply draw it first in your loop and everything will appear on top of it
7) SCROLL BACKDROP:
As above, if you were using a textured plain you can just "scroll object texture"
8) MAKE LIGHT light number:
You already CAN make more than 7 lights if your hardware & drivers will support it. However the main trouble is not knowing how many you can use, or how many the users of your games will be able to use. This is where Indi's suggestion comes in
9) CREATE DLL:
Umm lol A Dll is an externally made peice of code which can be used to add functions or commands to DBE or DBP (I think thats a good enough explanation altho some1s bound to flame me for it

) They require complex programming in C++ or a few other languages. Therefore just 'Create Dll' would do no good, unless you included the entire C++ program code after it, and DBP included a C++ compiler. This is literally NEVER going to happen, and would be close to pointless. Just including externally produced Dlls is much more efficient
10) Possibly update the TECHNICAL DOCUMENTS page?:
I agree, the documentation isn't exactly comprehensive. Most users with a background in Programming don't need them, but DBP and especially DB is marketted as a easy way to learn games programming, so much more NooB tutorials, with a progressive learning curve, and more detailed technically docs and examples would be welcome, even if I personally prolly wouldn't need them
11) Thank you for your time:
No problem dude