TBP staff will most likely focus on EA Civil War campaign next. However, it is 3 times bigger project than Raider Wars was. It will take time to complete even first part of the campaign.
However, it is still up to mission designers themselves what they want to do, even though we encourage them participating to the EA Civil War campaign development.
This being the case, we encourage people who like TBP, to make more missions and campaigns. You will find a lot of useful material from Freespace Campaigns forums.
Making missions, not to mention campaigns that please the general public is not an easy task. Even if we have gone trough the trouble to ensure that Raider Wars, or any other mission for that matter, will be completely playable, there will still be something we've missed. Please don't disregard our (especially IPAndrews' and Darkblade's) hard work on Raider Wars too hastily. Luckily the SCP team has also paid more attention to fred2_open lately, which should allow making of missions little bit easier on your mental health.
As for missions being hard, well the mission designers of Raider Wars (namely IPAndrews) encourages you to think. Think of different ways to approach a difficult mission, a way you didn't thought of first might just make the mission a lot easier. If Minbari fighters are little too tough for you, lower mission difficulty from the game settings and you should do fine.