So I'm level 38 and I have 250MP with 2 astral rings and a rolanbery pie, however I rarely even use half of my MP, would it be wiser to ditch the astrals and just get two +3 CHR Rings?
I would keep both sets if I were you. It all depends on what you need to do in the party. If you have to use a lot of mp then the astrals but if you find your not using much then you can switch to the CHR rings.
You kill one man, your a murderer Kill many and your a conquerer Kill them all... your a God.
I would stick with the mp except when you need to sleep something. Just try to use your mp more. That becomes very easy once you get access to cure 3 and curaga.