Fundamentally Saga and I, to an extent, mean different things by the term 'WIP' certainly when using the term for our stories.
I use the 'WIP' to refer to 'A story on which I am working, which will NEVER get posted until it is completed'.
Saga, based on the questions she asked, is using it more in terms of 'A story on which I'm working, which I post in parts as I go alone, before the story is completed'.
Also, I don't read WIPs, so some of the questions didn't really apply to me in the way they would to other people.
Nonetheless, as I enjoy all things related to discussing writing, etc. I thought I'd answer the questions. And I'm also going to share my answers here.
1. Who here is guilty of having an Abandoned WIP folder on their PCs?
I have an archive folder for each pairing which contains some ideas I had, or even a paragraph or two of stories that I've started and now know I shall never finish. However, these stories will not be posted unless I suddenly decide to finish them.
In fact, I did that just last year; an idea I'd had for my very first pairing (Starsky & Hutch) suddenly got turned into a story. It wasn't anywhere near as long as I'd originally intended it to be, but when it came to writing it I decided that the short version was all that was needed.
Other than this, my WIP folders are stories on which I am working and will finish. These stories won't be posted until they are complete, no matter how long they turn out to be.
2. How do writers feel about having given up on a story?
It depends on the story, the pairing, how far into the story I am. As someone who hates giving up on anything it's quite tough to say 'this idea is not going to work'. However, I have got better at it over the years I've been writing.
3. Do you feel sad, guilty, embarrassed or silly?
A little disappointed maybe (it depends on whether we're talking about stopping after a line or two or five pages) and somewhat irked at myself, but that's about it.
4. Do you lay low for a while and hope everyone forgets the story?
As no one will ever have seen the story, this doesn't apply to me. There will be no story for anyone other than myself to forget.
5. How do readers feel about being left hanging in mid-plot? Do you get frustrated, angry, sad or do you just shrug it off and find another story?
I don't read WIPs. I did in my very early days of fandom but having been burnt a few times, I made a vow 'never again' and now I stick to it. The only exceptions (and they are few and far between) are:
a) If technically the story isn't a WIP, i.e. it is actually finished, but the writer is posting in chunks. (Although even then, I tend to wait until all the parts have been posted).
b) I really, really, really trust the author and know her/his ethos about writing.
c) If the story is in fact not one of 'my' pairings, but is by an author whose writing I enjoy. Thus I tend, if the parts are short, to read them as they are posted. But as I'm not overly involved in the pairing, it doesn't matter if it is never finished.
6. As a writer, what made you give up?
With some pairings a loss of interest or passion in the pairing. In other cases, the idea just didn't come to anything or wasn't working.
7. As a reader, which WIPs do you remember most and really wish had been completed?
It's far too long since I read a WIP so, I don't have one. (At least not in one of my own fandoms).
8. Again, as a writer, could you ever be tempted to get back to the WIP and finish it?
No one would know there was a WIP for me to be tempted back to.
9. What would help you do that? A new muse? A new beta-reader (or even a support group of them) offering to devote themselves to getting a particular WIP finished?
10. Again, as a reader, would you volunteer to assist a writer in getting a particular WIP to completion?
N/A because I don't read WIPs. Unless it was a personal friend who was stuck, and wanted some help, maybe someone to bounce ideas off, etc. Then, yes, I'd be prepared to help, assuming it was a pairing I knew/wrote, or at least had some idea of from the person's work.
11. Would anyone here think it a worthwhile project to get a community going in which writers submit details of their WIP(s) and others offer their advice or services to get them finished?
N/A Again, not being a reader of WIPs or a writer who posts WIPs, it's of no interest to me.
Also it's not my ethos to work like this. As a writer, writing is a very personal thing for me, something to be done alone. Thus whilst I might bounce the odd idea off a good friend, or share a snippet of a scenario or ask a specific research question that I either can't put my hands on, or want to be completely certain of my facts and know they'll know as it's their field of expertise, that's all I do. I write alone, I get my ideas alone and I chivvy myself along. That's just me.
And it's not just with fiction writing I'm like this. I never did join study groups or things like that; I studied alone. The closest I came to it was when my best friend and I did a joint project as part of our pre-sixth form fortnight when I was at school. Even then if I recall correctly we separated the project into sections and she worked on her sections and I worked on mine.
I'm an only child and due to a lot of absences in my early school years due to severe tonsillitis (but it was the era where they didn't remove tonsillitis, even when I was hospitalised with one bout) I learnt to entertain myself from a very early age and was very happy to do so. So maybe my whole 'work' ethos stems from this.