Hello, I'm running Windows 7, and I really miss being able to expand individual folders with a little arrow (or +) as I could do on Mac OS. I'm not a programmer or developer, I'm a video professional using mostly Adobe software. The expanding folders is really my only reason for wanting to install Dolphin over Directory Opus, which I'm using now. But I've read on this site that Dolphin is still in development and may not work well. Could anyone please offer advise about whether or it's a good idea to install Dolphin just for that one feature that I miss? It seems like it might be meant for people who are very savvy about root level system stuff, and possibly not people like me who just need the folder option. I was looking at the download page, and it sounds like it has to install a whole KDE framework or something (I'm not a programmer, so excuse my lack of vocabulary and understanding in this area), and seems a bit heavy-handed. Can I just install Dolphin, like any other app running on top of WIndows, or is it more of a root level thing that will change my system (and possibly conflict with other software)? I can't find another file manager tool for Windows that offers that feature. Any tips or advice are much appreciated! Thank you!

You might hop over to the Windows forum and ask this as they would be more able to answer questions concerning KDE software running on Windows.
I'm not sure where you may have seen anything suggesting that Dolphin is still in development and may not work well. Dolphin has been working well for many years.
That said, a similar statement may be said about KDE on Windows, though I don't know how up-to-date that is as the KDE on Windows project has been around as long as KDE 4 (about 7 years) and I would guess that it is in a reasonably stable state. Several years ago, when I was still running Windows at work, I had KDE installed (around versions 4.2 - 4.4) and used Dolphin quite a bit without problems.