I have no problem with non-canon pairings in theory, even when they involve D and E, but like you, I like my stories to stay true to Austen's characterizations. If a character changes, that change should be done in a realistic way so that we can see how this person evolved from being the one in the book to the one in this story. For some of the pairings you mention, it is very hard to imagine how they could be done in anything like a realistic fashion.
For instance, you mentioned Darcy-Charlotte. Unless this is a story set a long time into the future when both are much older, I can't imagine any circumstances under which Darcy would offer for Charlotte. She is even further beneath him than Elizabeth, and she is neither pretty nor witty. Darcy being the man he is, he would never feel the type of passion for her that would cause him to stoop so low in marriage. If for some strange reason they did end up together I can see them treating each other with respect and maybe even liking, but nothing more.
As for Caroline and Anne, they are not so far fetched, but even then I feel like it would need to be a few years in the future, a future in which Elizabeth has never appeared, but it's obvious that at the time of P&P he is in no hurry to get married and shows no inclination to either Anne or Caroline. It would take time, in my opinion, for him to reach the point where he feels like he needs to marry and so might as well marry one of these women who are waiting in the wings. I think it would be interesting to see a story where Darcy does marry Caroline, in which Caroline is not vilified as she so often is in these things, but treated as a real, flesh-and-blood young woman, who is socially ambitious but not without conscience and heart. The story would follow both their growth, but especially hers, until they become a couple who really love each other and are happy together. I know some people would doubtlessly like to hit me for the very suggestion, but I think it would be fascinating if well done.
Elizabeth and Bingley are a challenging couple, but I have seen it done very well (Particular Attachments). It's easier to imagine Bingley's affections settling solidly on whoever he is with than Darcy's. As for Darcy-Jane, I know there are people who favor that match, but I don't know. To me they're too much alike in the wrong ways. They're both calm, reserved people who benefit from a lively partner to draw them out. If they were married, Darcy would probably become more serious, not less, and Jane--I don't know. It's not in her nature to be discontent, and Darcy would always be good to his wife, but he also has a very strong personality and would possibly be overbearing without realizing it. Would her perpetual optimism (she smiles too much) ever get on his nerves? Would his caustic wit distress her? To me, they're a pair without much chemistry, but I would still read a story about it.
For instance, you mentioned Darcy-Charlotte. Unless this is a story set a long time into the future when both are much older, I can't imagine any circumstances under which Darcy would offer for Charlotte. She is even further beneath him than Elizabeth, and she is neither pretty nor witty. Darcy being the man he is, he would never feel the type of passion for her that would cause him to stoop so low in marriage. If for some strange reason they did end up together I can see them treating each other with respect and maybe even liking, but nothing more.
As for Caroline and Anne, they are not so far fetched, but even then I feel like it would need to be a few years in the future, a future in which Elizabeth has never appeared, but it's obvious that at the time of P&P he is in no hurry to get married and shows no inclination to either Anne or Caroline. It would take time, in my opinion, for him to reach the point where he feels like he needs to marry and so might as well marry one of these women who are waiting in the wings. I think it would be interesting to see a story where Darcy does marry Caroline, in which Caroline is not vilified as she so often is in these things, but treated as a real, flesh-and-blood young woman, who is socially ambitious but not without conscience and heart. The story would follow both their growth, but especially hers, until they become a couple who really love each other and are happy together. I know some people would doubtlessly like to hit me for the very suggestion, but I think it would be fascinating if well done.
Elizabeth and Bingley are a challenging couple, but I have seen it done very well (Particular Attachments). It's easier to imagine Bingley's affections settling solidly on whoever he is with than Darcy's. As for Darcy-Jane, I know there are people who favor that match, but I don't know. To me they're too much alike in the wrong ways. They're both calm, reserved people who benefit from a lively partner to draw them out. If they were married, Darcy would probably become more serious, not less, and Jane--I don't know. It's not in her nature to be discontent, and Darcy would always be good to his wife, but he also has a very strong personality and would possibly be overbearing without realizing it. Would her perpetual optimism (she smiles too much) ever get on his nerves? Would his caustic wit distress her? To me, they're a pair without much chemistry, but I would still read a story about it.