a) Meh, I think the heat cost is so extreme as to make it only 'spammable' for a very short time. That short time would give us some much needed utility however, as well as providing extra defense before a cast chain.
b) PTs can already spec into permanent ranged snare (which is what prompted many mercs/mandos to ask for an 'equalizer' in the first place)
Good points, and I agree with both. I just don't know if the general populus of maras/sentinels will. :P