Yeah I had something similar when I flashed something that wasn't compatible with the ROM. Once I reflashed recovery I was good. Glad you got it working.
I am glad this is all sorted, you did the right thing. Yeah, sim unlocking is possible but mine is unbranded and unlocked so I haven't really looked into it. To be honest with you, rooting and installing custom ROMs is extremely easy, it's just the Chinese software the pretty much messed up everything on your older device. I'd say wait and get an unbranded and unlocked one to avoid the hassle of learning how to unlock it, using ADB commands and doing things that may or may not brick your device if something goes wrong, why take the risk on a $500+ investment?
After you get an unlocked device, we can then talk about rooting and custom ROMs and whether you really need them. Yesterday I had a terrible experience with my device as it wasn't connecting to any network the whole day after I updated its firmware. I tried all the modems/radios available, several custom ROMs and nothing was working; I then decided it was time to download an install a RUU and that fixed everything, and to be honest I am going to stick to the stock 4.1.2 ROM that came with the device and prepare it to receive OTA when it comes.
Haha , no wonder you were missing yesterday So how and where can I get an unbranded and unlocked version of the phone?