Disk configuration on ReadyNAS Ultra 4

Just a quick update and a question about this : I've made the reset, everything is back online, now it says this under volume;

Ch 1 : WDC WD15EARS-00MVWB0 [1397 Gb] 1392 Gb allocated
Ch 2 : WDC WD15EARS-00Z5B1 [1397 Gb] 1392 Gb allocated
Ch 3 : WDC WD20EARX-00PASB0 [1863 Gb] 1392 Gb allocated
Ch 4 : WDC WD20EARX-00PASB0 [1863 Gb] (nothing is written yet, the drive is flashing green, I think other drives are finished and this one is in resync)

It's been almost 15 hours since I started the process and on the box screen it says 'Resync C: 10.7%', and on the admin page, sometimes it says something like 24 hours remaining, but sometimes is says 388 hours remaining!! The drives are empty..., is that normal??

Does that mean that the first 3 drives are 'ready' and only the 4th one is processing?

And finally, can I shut down the NAS, move it elsewhere in my house, open it up again and then starting using it while it still resync on the 4th disk?

Thanks a lot for your help!