1) If you are talking about the OP of the Wrathcalcs thread then the answer would be no, not always. Hamlet and Tecton will often update the spreadsheet and post a new version in a reply to that thread, so your best bet to find the most current version of the spread is go to the most recent post, and continue backwards until you see one attached to a post. (I would link the most current version for you, but I'm at work and EJ is blocked here)
2) Answered in one.
3) Feng's ring of dreams is missing the normal and heroic versions; I have already reported this issue and it should get fixed in the next version. For now you can leave that ring blank (which it should do automatically when you import your character) and manually add the stats you get from the ring after reforging. To add stats you simply type in the number you want to add in the middle row at the top of the sheet, under your default stat numbers.
4) You did not indicate how much hit under the cap WC is showing you are, but this could be a result of several issues. The version of WC you are using is EXTREMELY old and outdated, this might be the case if you followed the link from the theorycrafting thread on EJ. I think Hamlet wrote "The most current version of the spreadsheet always lives here" but unless it changed recently, I believe that link takes you a very old version. Even if you have a MoP version of the spreadsheet, the earlier ones had incorrect stat values for several items which was fixed in later versions. Make sure all the items have the correct stat values.
If you are using a newer (or newest) version and you imported your character, there are still some glitches that can occur. I'm not sure what causes this but I have had times where it will seemingly import my character fine with all the correct gear/reforges, but upon closer examination it will have imported green/orange gems that do match what I actually used. So I would go through every single piece of gear, and make absolutely certain the gems/enchants/reforge match what is accurate.
Finally if you manually updated your character, there is still the chance of human error. So it's best to just double check that you didn't make any mistakes.
Remember manually adding stats is good way to compare gear/gem/reforge options if you are struggling to import your correct gear.