Holy - so you have EK18 running on your phone with the CWM recovery GPOT? When you deleted the sh script from update.zip, the update still worked??? I would think they (sprint) would have calculated an MD5 on the update.zip file and then thrown an error message during the update process since the MD5 would not match since you modified the update file. If not, then they (sprint) are idiots.
At any rate, please confirm that you are back to gingerbread with CWM recovery. If so, then we all need to do this as well. However, I believe you skipped a step. I believe the process you would have followed is (and please confirm this GPOT):
1. Flash shabbys ed23 odin
2. Use the first update file uploaded by firehak to get to EF27.
3. If not rooted, use any of the Root METHODS that work (There are at least 2 that I know of)
4. Delete install-recovery.sh from system
5. Delete install-recovery.sh from the gingerbread update.zip
6. Proceed with updating to GB.
7. install cwm recovery using shabbys image (can be found on these forums) and ODIN.
Is this right? If this works, then we are a huge step closer to being rooted. And, with what I have learned, I believe I can created a rooted ROM from there that we will need to load on our phones with ODIN, or, if I can figure out how, with a new update.zip file that I would create (this method might be harder than I think)
FYI - this is a method I was researching - so if you did get this far GPOT, you saved me a ton of time. Thanks!