Another editor I tried recently sucked, but had a feature I really liked. When changing projects and opening, for example, the index.html page, all linked files were opened along with it, so a .js file and a .css file referred to in the head tags were also opened. I usually have to go and open them all anyway as I am often constantly tweaking them, the css file especially, and I found this feature surprisingly clever. I wouldn't think it would be that hard to implement an option for this behaviour and it would add a lot of usability to WeBuilder. After twenty years of clicking mouse buttons, my wrists and hands are nearly ruined so every click less is valuable to me and opening one file and having associated files open with it is, in my opinion, a worth-while addition to the editor.
Thanks for your time and consideration.