I'm not an expert on this stuff - others on here are - but my observations are:
1. The SNRM, both upstream and downstream, have been pretty stable, which is good.
2. The number of errored seconds looks to be low, also good.
3. There have been a few bursts of FEC errors, of the order of 100,000. Roughly one or two bursts per day. These are errors that were corrected, so won't have caused a problem - I believe these are basically errors that are effectively corrected by the interleaving on your line. If interleaving were removed, it's possible that whatever caused these FEC errors would cause uncorrected errors on the line. However, I don't really know whether 100,000 FEC errors is a large number in the great scheme of things.
I don't know if DLM takes FEC errors into account. If it doesn't, I would think it will eventually remove interleaving and you can see how the line fares then now that you are monitoring it. However, if it does take FEC errors into account, then I don't know what it will do. Hopefully someone else who has studied this stuff will come along and be more definitive!