dedupe on addition

You can currently do this yourself by un-shuffling then re-shuffling after your searched song is playing.

Personally, I don't want this to happen automatically. If I deliberately insert an item into the current running order, I don't want it second-guessing what I want removed from the running order because of it. What if I was deliberately building a playlist that had something specific in more than one place? Such as a deliberate track of silence at a certain point.

you put in "space between" in title search, and it shows 10 tunes that match.

If all 10 of those tracks are named the same, then it will say "space between (10)" on the screen, and when you select it, it will play all ten of those (just like you wanted). The only way that it would play just one of them is if they were all deliberately named differently.

Personally, I prefer to deliberately name all of them differently. There are so many available versions of Rush's "Closer to the Heart", for example. I do this on purpose so that they can be distinguished from each other in a search. I can't think of at time that I'd ever want to hear all the different versions queued up one right after the other.

Others have wished for the exact opposite of the thing you're wishing for: When it says "space between (10)", they want to be able to sub-select out of that list of ten. I agree with this, but only where it applies to completely different songs with the same title. For instance, I get "Mother (5)" on my player, because there are five completely different songs which happen to share the same title on my player. I could rectify this by renaming them "Mother (Cyndi Lauper)", "Mother (Pink Floyd)", "Mother (The Police)", but I just haven't bothered to do that.

since title search only works from the starting

This could be useful in some cases, but it would make other things difficult.

I had one situation where I know it would have helped me. I had a song on my player that was titled "Greetings (Deckard Cain Rap)". For those familiar with Diablo II, this was a hilarious joke song that the Blizzard people did. So one day I was talking to the son of a friend who was also a Diablo II fan, and I told him that I had this funny song he should hear. So we went out to the car and I tried to do a search for the song. Problem is, I couldn't remember that the title of the song was "Greetings", I thought the title was "Deckard Cain Rap" so I kept typing D-E-C and coming up empty. So in that case, a fuzzy search would be useful.

But you also have to understand the flip side. If the fuzzy search didn't start at the beginning title, then each keypress of the fuzzy search would return MANY MORE matches than you wanted. It would cause the fuzzy search to require more keypresses per song than it does now. Some of this could be worked around if they "ordered" the search results (beginning-of-title first), but then you would have to scroll down to find the middle-of-title songs. Still, maybe worth doing if they could get it right...