I forced myself to learn to use Allegro 5 years ago and came back here for help many times. I am glad I did as it is a much nicer beast with modern features. Not difficult at all to use.
As for map editors, I always make my own. In fact, when I work on a game, I always make the map editor first. For my Deluxe Pacman 1 game, I created the editor with Allegro 4, and with Deluxe Pacman 2, I created the editor with Allegro 5. It helped me get used to programming Allegro 5 as well as iron out how I wanted my map format to be. By the time I started coding the game itself, I had levels already created and ready to test the game out with and I understood how I wanted the map levels to be laid out data wise.
I highly recommend programming your own level editor from scratch, it's very satisfying to do and you can include it with your game which extends the life of your game as the people love to make their own levels (I had some that created over 500 levels for my Deluxe Pacman 2, which astounded me).
They're not difficult to code. With my Deluxe Pacman 2 editor I was proud of it as it was super simple to use the way I designed it. You just drew the level like you would with a pencil and paper, drag the mouse around and the lines were put in place logically... levels were fast and simple to create etc... give it a shot!