ICloud storage issue; Restoring iPhone calendar from iMac after accidental iCloud deletion

Question

I set up iCloud to back up calendars and contacts and for find my phone.  Initially, it seemed to work alright.  Then I got messages on iPhone that there wasn't enough iCloud storage, even though the storage tab showed that I had used none of my iCloud storage at all.  So I turned off iCloud/contacts.   In iTunes I switched back from iCloud backup to backup from my iMac. 
Later I got the same message about not enough room in iCloud even though only calendars involved.  So I truned off iCloud/calendar on my iPhone and was given the choice of keeping the calendars from the iCloud or deleting them (a foolish choice without a failsafe!!!).  I clumsily and mistakenly hit delete.  My calendars have most recently been synced with my new iMac and appear on the iMac and should also be in TM.  But right now there is no data in my iPhone calendar.
When i go to calendars within the iiphone calendar there is a check next to Calender under "from MY Mac" and no reference to iCloud.  (There are no separate calendars for me, my wife, and joint.  Does this mean somehow these calendars have been merged because of iCloud?)
I don't want to do another sync until I can make sure that the sync with the iMac will resotre the calendar(s) to the iPnone.  How do I do this?
Do I have to do anything on the iMac before I try a sync?
How do I avoid these problems in the future?  The only thing I really would like from iCloud is "find my phone".  How do I keep that capability without backing up or su=yncing otherwise anything through iCloud? 
Is iCloud still Beta?

Answer 1

Apple walked me through this and helped me revert to backing up on my iMac, using iCloud only for find my iPhone and iMac.  The process, however, is not straightforward and what the respective mac and iPhone support people (yes, they have that kind of specialization) led me through was clearer, if somewhat convoluted, than any instructions on Apple's support or community pages.
Since my main concern was not losing my calendar and contacts information, the key was saving that, via export, to my desktop.  Sorry I didn't write down all the other steps - but I see that as Apple's job.  Back in the days of the IIC, Apple's manual was a model of clarity and completeness at the same time.
Bottom line is while my immediate concerns were resolved, the underlying iCloud storage issue was not.  On my iPhone, I was being told that my attempts to backup to the iCloud failed because I didn't have enough storage, even though I determined almost none of my alloted space was used.  This issue is not helped by the multiplicity of settings relating to iCloud, or the interfaces (such as the iCloud on the iMac through Mavericks) which present a screen of icons without additional information.
For my purposes, iCloud remains Beta.