If a rocky world is large enough (not a gas or ice giant) can it have helium from the primordial disk in its atmosphere? When planets are formed do only gas and ice giants accrete hydrogen and helium? Does this accretion have to be beyond the "snow line"?

In other words, would all hydrogen or helium in the atmosphere of a super-earth come from outgassing (radioactive decay, etc)?
The snow line is the inner radius from the star where the water condenses onto dust and larger particles as ice (ie snowballs).  The hydrogen and helium never freezes out.  Planets start forming by accreting these particles (with or without ice but definitely not with H or He), but when a growing planet reaches a sufficiently high mass, it starts to pull in H and He (and more importantly, can hold onto them as they have low atomic mass and thus tend to escape quickly unless there is enough gravity). Exactly what mass that occurs at depends on a lot of factors (temperature, pressure, etc), but it happens below Neptune's mass and in part of the super-earth mass class.  The upper range in mass of the super-earth are also called mini-Neptunes or gas dwarf planets and from their typically low densities it is clear that they are mostly composed of H and He.  

However, beyond the snow line it is more likely for a planet to grow to a large mass since more of the surroundings has condensed out of the gas into small particles, therefore accretion is more efficient.  So, it may be that mini-Neptunes are usually forming beyond the snow line and then some of them migrate closer to its star.  But, I don't see any reason to doubt that some of the many mini-Neptunes with H and He found by Kepler/K2 inside the snow-line were formed in situ.  I am not an expert in this field, and perhaps the experts would disagree.