What else are you doing now? What's your other priority? Is the creation of new maps a priority? I think most fans of the game would like to prioritize improving the gameplay over creating new maps. I think when choosing between these two priorities, most fans would vote to improve the gameplay instead of creating new maps. If necessary, I can write such a vote.
People will play little on new maps if the gameplay is burdened with a number of unpleasant things that make it much worse than it could be. For the same reason, you have a fairly small influx of new audiences. I can tell you what exactly would be worth changing to improve the gameplay.
First, I appreciate your enthusiasm. I'm glad there's still people who are very passionate about Forgotten Hope, I know I certainly am

I will say that at this time, the current developers of this mod are focused on
multiplayer gameplay. So yes, we're working on creating new maps, new guns, vehicles etc... to give our players new content. Singleplayer is unfortunately not a priority of ours. I understand there are a lot of people who play this game who only play singleplayer, but the majority of our developers are better equipped to mod the multiplayer side of the game.
Singleplayer in Battlefield 2 was more of an afterthought by DICE, and as such, lots of aspects about it are hardcoded and not easy to make meaningful changes to. Not to mention that the amount of people out there who both know how to mod singleplayer for this game and want to mod for such an old engine are few and far between. So just as the original Battlefield 2 game focused on multiplayer with singleplayer added on as an option for some maps, Forgotten Hope 2 is doing the same; we're a multiplayer focused game and when we have time and resources we try to attend to singleplayer issues as best we can.
We don't currently believe that our "gameplay is burdened with a number of unpleasant things that make it much worse than it could be" with regards to our
multiplayer gameplay. There's certainly some things we'd like to improve, but they are not related to the singleplayer at this time.
That being said, we are always looking for people who are able to make improvements to our singleplayer side of the game; namely making navmeshes & GPOs for new maps so they can be enjoyed by the singleplayer community as soon as possible. However, outside of providing new content, there's not much we can do. I believe that our singleplayer already incorporates most, if not all changes/ improvements that every other Battlefield 2 mod includes. If there's something that they've done that we haven't incorporated yet, it could be something we could look into.