With the exception of the "path finder" (which is generally not a tool and usually something built in to the game logic, unless you are doing pre-baked navigation through a search space), the items you listed sound like potentially viable tools in general. Whether or not they will be useful for your game depends, of course, on the kind of game your making and its specific design. If you need all those kinds of tools, then by all means build them. But build them because your game needs them, and then consider if you should release them as open source projects -- you may find that they end up being far too specific to your personal game to be that useful to others.
Tile and map editors tend to be very commonly needed. It's quite hard to make a suitably general-purpose one, but for your game, it may be something to consider building.
If your goal is to make a game, you shouldn't be focusing your tools development around "what tools don't exist for free that I could make and release," but instead "what tools do I need for this game?" It will be a far more productive line of inquiry.
Not all 2D games require the same kind of assets or technology -- for example, not all games require path data that is complex enough to warrant a custom tool to author that path data. Many games that do could get away with using existing vector image editing programs to author the path and massaging the output format from the image editor. Likewise with "texture generator" -- by which I assume you mean a tool for tweaking inputs to various procedural texture generation algorithms or something.