that version of EB28 you have is really really basic.
it was pretty much only intended to be a stepping stone to get you to EB28.
go back to SDX and flash a full on ROM.
Won't lie, Keylime is one of my very favorites.
Flash that (it has the kernal in it) and you'll get all of the "fixes" that are out right now.
From there, load your apps and all of that.
I highly suggest flashing the new clockwork recovery before flashing the new rom
clockwork found here
clockwork recovery for rfs/ext2/ext4 systems - sdx v0.4
reboot to recovery,
flash KeyLime (found here - [NEW UPDATE]KeyLime28 v3.3(5/28)
) or any other "full" rom
reboot to system
reboot the phone a couple of times, let it totally load each time, you should notice that it loads faster and faster each time.
load all of your apps.
reboot to recovery
convert file system to EXT
do, system ext2 data and cache ext4 (seems to be the best balance of speed and stability setting them all to ext2 is "supposed" to be faster, and it will get you a higher quadrant score, but I don't know if the performance can actually be noticed, try it and see what you think)
From there, I'd recalibrate the battery
test out your gps and see if it is working, then try one gps fix at a time til you get it fixed (you might not need to, mine worked as soon as i flashed the ROM)
I recommend barnacle for your wifi tether. seems to be much more stable than the built in wifi tether
beyond that, you should be loving your phone.