Don't use that method to root. The zedomax kernel isn't completely stable and is outdated now. For rooting EL29, the easiest way is using an odin one click pre rooted for EL29. You could also do the same thing but for ics if you want the stock ics. The latest version is FF09. If you want to use a custom rom, make sure to just read read read! Be sure you know what you're doing before blindly flashing something as using ics incorrectly can brick your phone. If you want to use a custom ics rom, I'd suggest rooting EL29 and getting clockworkmod, and then flashing a rom. I personally like the Blu Kuban rom.
If you want to stay on gingerbread for now until ics is officially released, I'd suggest the blazer rom. It's incredibly stable and amazing all around.
Also, yes, if you stay on stock gingerbread, you'll eventually get the official OTA for ics from Sprint.
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