From your point of view IRC or WS will do the same, it's just the protocol behind that changes. By default it'll be WS as this is what the twitch website uses.

Both will connect you to chat when a streamer goes online and disconnect when going offline. If connection is dropped, you'll be reconnected. Here's there's no "2" limit, this is just for the channel points mining that it exists.

I don't really know if limitations are different depending on which is used, but I think that in normal use case no limitations will be hit either way.