Mary in the Roman Catholic Church - intercession or idolatry?

I don't know much about RC practices, which his why I am using "from the outside"While driving home, I sometimes listen to evangelical radio discussions. These are the scholarly type, not the rabble-rouser type of discussion. For example, "The Bible Answer Man" is one such program.The question of the RCC sometimes comes up for discussion. Various issues are mentioned. I don't recall "maryolatry" as ever mentioned.The chief objection that evangelicals have to RCC, is over salvation. They insist that salvation is by grace alone, due to faith alone. They criticize the RCC for salvation based on works. Whether they correctly characterize the RCC position, I do no know.My main point - the issue regarding Mary is apparently not seen as significant. Doubtless the evangelicals don't agree with it, for they don't follow those practices. But they apparently do not see it as idolatry.It might be different among the rabble rousers.

That might make it a quaint traditional practice, perhaps even a practice that could not possibly work. But it isn't at all obvious why that would make it idolatry.I seem to recall that evangelical denominations have their own quaint traditional practices, although perhaps not as many as the RCC. (I don't want to pursue this, however, as it is OT).

Is heaven a kind of prison, such that when you are there you lose the power to intercede with God?