Should Darcy have interfered with Bingley's love for Jane?
Definitely from a modern-day point of view, we would say Darcy should have minded his own business. But let's look at it from Darcy's point of view - that of a 19th-century upper-class gentleman. He knew what society was like at that time - he knew that if Bingley had aligned himself with a lower-middle-class family (particularly one with an obnoxious, shrewish mother and very flirtatious younger sisters), his future in society could have been damaged. Darcy truly cared about Bingley and his future, and he didn't know Jane from Eve. It seems cold and unfair to us, as we have the point of view of knowing what a good woman Jane was, and that she truly had fallen in love with Bingley, would have tried (and probably succeeded) to be a good wife to him, etc.
But again, Darcy didn't know any of that. All he knew was that his friend was potentially making a very damaging mistake, and that society at the time was unforgiving concerning these types of situations. Darcy did not want Bingley to suffer.
Your question is really more of personal opinion-whether you like the character or not. Personally, I feel Darcy should NOT interfere, since he is basing his opinions on a "class" issue. He objects to her family, and is not considering Jane's own character.
No. Plain as that. No. Darcy should not have interfered with Bingley and Jane.
However... I can understand why he did. He looks out for Bingley. He looks out for Bingley and wants him to be happy. He did not think that Jane was in love with Bingley and Darcy didnt was Bingley to love somebody and marry somebody who didnt love him back.
Then again Darcy was being prejudice so perhaps the should have waited to find out first.