You can’t edit with H264 in FCP, and you shouldn’t edit with Photo Jpeg.
Convert the H264 footage to ProRes HD 25 and edit. Photo Jpeg can be edited but can’t do realtime effects.
So convert this to ProRes aswell.
For the 29.97 footage , you have 3 options.
a.Conform to 25 ( plays slower, including audio) in Cinema Tools.
b.Convert to 25 with Compressor or Jes Deinterlacer
c. Just edit them in a 25 timeline, but FCP wil skip 5 frames every second ( not an option with moving images)