I just want to make sure I have this right before I do it and mess everything up. 

I have all of my contacts in zoho crm already. I then set up Deals (or factfinds as I have renamed it) for each sale and I included the contacts in there but left everything else more or less blank and export the CSV file. 

I have now gone through the CSV and completed it. I want to now import that back in which I am fairly sure is just clicking on Import, choosing Zoho crm and then uploading the CSV file. 

I just want to make sure that:

1) That is correct,

2) That the fact I have added more customers and deals (or factifnds) since exporting the CSV file will not be a problem,

3) If there is a problem, is it easy enough to revert back to where I am today,

4) If there are problems (maybe with the formatting for example), does it tell you where the problems are so you can work through them and fix them or something else?

Cheers.