Are you aware of relevance equations as an alternative to conditions.
www.limesurvey.org/manual/Expression_Manager
In your last sentence you articulated the following rule:
Display Q2 if Q1 has more than one answer item ticked.
On the Expression Manager manual page you will find some functions described.
One is count.
count the number of answered (non-blank)questions in the list number count(arg1, arg12, ..., argN)
In the relevance field of Q2 you could enter something like {count(q1.NAOK)>1}
The curly braces are not needed in the relevance fields.