1. What do you think of canvas as a medium for straight photographers?
I prefer a normal print, but it's not something that would bother me.
2. Is HDR a comfortable technique for straight photographers?
If you mean the rendered look you get from some software programs, I mostly find them awful looking. Shadow is an essential part of photography IMO, and removing it tends to be a bad idea. Do I sometimes lift shadow details..yes I do.
3. Should straight photographers boost colour saturation to the threshold of having the observer wonder if "this is real" but unable to tell with certainty?
Its very much like your choice of film, I see digital as similar..you can set it up in camera to your tastes, or you can pp afterwards. I have no problem with either. Have I used shots from the camera with no pp, yes...do I use pp..yes I do.
4. When an observer states "it looks like a painting", do you feel comfortable or uneasy or a little bit of both?
No because I am very aware of.."the photoshop" look. And it is not something I have ever desired.
A few things to mention here. As I said above, even the purist photographer has a choice of setup in camera, or a brand/type of film. So even they have some creative influence on results and the "look" shall we say.
I boil it down to "enhancement" and "manipulation"
They two are very different. Enhancement is anything from saturation, contrast, sharpness, tones/hues, shadow/highlight details, etc etc
Manipulation to me, is adding or removing elements that are not there. For example rendering a photoshop sky in, taking objects out (not dust spots though!), using selections of multiple images and merging them. Adding light effects that were not present etc etc.
Out of that I have no problems with the ist, and I will not do the 2nd. I would get no satisfaction from that myself. Each person can make their own choice on this one, you have a selection of tools available to you, and you can pick which ones you want to use.
So I take a lower pp point of view here, I limit it, and will not cross some lines. I feel its no different to making a film choice. But, I do think that there is most def an "overprocessed" look, and that sometimes it can work, and other times it looks just nasty. I am not a high saturation shooter myself, I never did like velvia that much, but some love it. Even a purist velvia shooter, is using enhancement by his choice of film.
I would also add there is def a point that digital art takes over, and a photo ceases to be that. I remember seeing some work by a photographer, very nice indeed..with animals, but with obvious manipulation, adding balls and objects that were not there etc. That is not acceptable to me (I would never do that), but I can respect the right of each to do their own thing. The last think I want someone to think of seeing a photo of mine, is "photoshop", 9 out of 10 lightroom would be as far as I would ever go. The biggest problem is, that very many are doing lots of heavy processing, and its not as popular to take a more restrained or minimalist route..hence the reason its so popular.