Are you editing all the 30p, 24p, and 24pA footage into the same time line? I'd hope not, unless you've removed pulldown from both 24p and 24pA footage, and converted your 30p to 24p.
Other than that, your best export for anything in FCP is File>Export>QuickTime Movie using current settings and making the movie self-contained. Then quit FCP and use Compressor to prep the files for DVD. The DVD format can handle 30p (which is 29.97 anyway) and 24p (23.976) without any problems.
For future projects, it's really a bad idea to shoot in mixed frame rates.
As for 24p not being "true 23.976"... both it and 24pA are recorded as 29.97. Both start life as 24p (23.976). The difference is in the pulldown cadence. FCP's pulldown removal only works with the advanced 2:3:3:2 pulldown. To remove the 3:2 pulldown from 24p, you'll need to use Cinema Tools to do a reverse telecine for each clip.
As for your 30p footage, which is the real wrench in the gears here... you have two choices.
1) You can leave your 24p footage at 29.97, and use Cinema Tools to telecine the 24pA footage back to 29.97 (by adding the same 3:2 pulldown that the 24p footage has), then edit both on a 29.97 time line with the 30p footage. The major disadvantage here is that you end up with interlaced frames in both 24p and 24pA footage, which defeats the purpose for shooting progressive.
2) You can reverse-telecine the 24p footage, then convert your 30p footage to 24p (23.976), and edit all on a 24p (23.976) time line. This, I feel, is a better option. Getting your 30p footage to 23.976 is going to be tricky, though, and you may sacrifice some video quality in doing so. Cinema Tools will help you do it. Note that simply forcing the time base to change from 30p to 24p will only create an 80% slow-mo from your 30p footage, so you'll have to actually conform it which will end up deleting frame.
Which way you go, I guess, depends on what the bulk of your footage is. Either way, something's going to take a hit, so make sure that it's the one of which you have the least amount of footage.