For a columnfamily in a keyspace which has RF=3, I'm issuing writes with ConsistencyLevel.ONE.

in the configuration I have:
- memtable_flush_after_mins : 30
- memtable_throughput_in_mb : 32

I'm writing to this columnfamily continuously for about 1 hour then stop writing.

So the question is:

How long should I wait after stopping writes to that particular CF so that all writes take place and data contained in the CF will be consistent.
Which metrics should I be checking to ensure that the CF is now consistent?

And additionally if I was using ConsistencyLevel.QUORUM or ConsistencyLevel.ALL would it make a difference?
Would reducing the RF=3 to RF=1 would it make my life on this decision easier?