I don't recall a "Mark", but I can describe two ways in which an expert might tag your question, and not respond.
I don't know if it's still in effect, but there was a time when the management assigned incoming questions to experts who are logged in, and informed them of the assignment. If they weren't, in fact, logged in, didn't get back to check, or weren't interesting in answering the question, that would explain what you saw.
A more common explanation is that, in order to look at the entire question, it's necessary for the expert to "lock" the question. The initial lock is for 1 minute, and additional locks are for 5 minutes at a time. If Mark looked at the question, and decided he wasn't able or willing to answer it, that would also explain what you saw.
If you're in a "community property" state, all bets are off in regard exactly what goes on MFS returns, but EIC is not allowed on MFS returns. If you're not in a community property state, it's likely that, on your separate MFS return, almost all of the NOL could be carried forward to 2011. However, your wife would be paying taxes on her earned income (less the standard deduction
and exemption) at the higher MFS rates. If you your business is profitable in 2011, this may legitimately reduce your taxes.
On a joint return, income and losses from both spouses are combined on the return, so your NOL reduces the joint AGI, whether or not it is considered to reduce "earned income". I haven't had an opportunity to check whether an NOL reduces "earned income" for the purpose of the EIC. So you're correct that the NOL reduces the EIC.