This issue is aggravating, can't install 3-4 apps on a brand new one without it giving this error, or receive texts or emails. The phone was advertised with 8GB of internal storage, not <1

Is there no way to re-size the partitions or re-size the space apps use? Why is it split in 4GB/4GB?
Let me put it this way:
there is 3.85GB of App storage, most of which is being used by "other" which takes up 2.76GB, with no way of seeing what that is or how to remove it, my last HTC phone had only 1GB but at least it had all the room available to it to use. System apps only use 565MB, with 553 available to me right now after removing everything i installed myself. I have less than 1GB of free space to use? wtf?
Now under phone storage is different, it lists 4.15GB space with very little used, totaling 14.53 MB, why can't apps use that room? or anything else for that matter? My SD card is 30GB, I don't quite enjoy having to constantly keep moving apps around on and off my phone in order to use one thing.
My phone is Rooted w/S-OFF, anything I can try? The page about swapping SD card and internal storage wasn't in English so I'm lost with that.