I tried narrow and travel and I must say that travel is awesome (although I wonder why do we need both since narrow can be implemented via travel with few options) and exactly as I described it. ".." is cool and very needed but one thing needs to get implemented: way to quickly clear the search. Perhaps in travel mode single ESC will clear search and double ESC will exit the mode.
Other fix that is needed: arrows do not work while they should, sometimes you want to narrow it down and then just use arrows if file names are too similar so you can't pin point char difference quickly.
Automatic reentering, comparing to narrow is what is needed for extremely fast file system browsing.