I really do not understand why you find shredding and bending more difficult with P4 tuning. For easy and accurate bending you need to use the right string gauge to have strings with the right tension. For shredding the P4 will require that you learn some new movements with your fingers and your wrist. Once you have learned them shredding and sweeping are just as easy (or as difficult) as with the standard tuning.
5th tuning can be obtained by stringing the guitar the other way round: the thickest string on the bottom and the thinnest on top. Keep the open string tuning E A D G C F top to bottom or transpose it as desired. You can play your guitar as normal, and you will hear the right scales and chords, but the intervals go down in stead of up when you play the next string.
Using barre chords for rhythm guitar in a band is generally to be avoided, except when you use an acoustic. I can really think of no major guitar player who uses barre chords. In a band with more than 3 instruments including drums you will try to divide the octaves between the different sounds and instruments, like the keyboard player will generally not play bass on the keyboard when there is a bass player to do that job. Barre chords generally go over 2 octaves and take up lots of tonal space. Chords with 2 - 4 strings are much easier to place successfully in an arrangement and leaves more space to the others. The P4 tuning is perfect for this purpose because once you have learned it you will have total freedom to improvise with chords and to vary the rhythm playing to the benefit of the song.