Ashley
1) It's really not that bad for simple platformers or top-down games, but as soon as slopes and other shapes are introduced, using sprite objects for collisions can become a real hassle.
2) Ok cool. Just making sure!
3) Yeah, kind of ^^; I always got complaints on my earlier level editors not having these features, so I made sure to always add them. I even went so far as to rotate/flip/mirror groups of tiles like tetris pieces..although that was a bit much!
4-5) Glad to hear it :)
I completely understand not wanting to reinvent the wheel, and it makes perfect sense not to dedicate so much time on a robust image editor when tools like PS exist. However, I feel that tiles are one of the few exceptions here. Levels are arguably the most important part of the game and we need to be able to work on them quickly and efficiently to get all of our ideas in there and make changes, no matter how large, as needed.
Having used Tiled, Ogmo Editor, DAME, GM editor, Stencyl editor, and a handful of my own custom level editors throughout the years, I feel that the features I mentioned are quite essential and in no way "fluff". They will definitely be used by everyone!
Also I know it's a big list and everyone is making their own suggestions - we just want to voice our concerns before it is too late and you decide to move on to the next big feature!