3) What's the benefit of mining a full node? I've only ever just minined to a pool, I don't really understand that aspect of this.
You do not/should not mine to the node! The node is simply there to support the Bitcoin network by well, having another full node on it for storing/distributing blockchain info.
Be it solo pool or normal pooled, mining requires the pool you are mining at to have the fastest possible connections to the BTC network along with wide distribution of that access to be able to monitor chain activity for block changes and notify the network when you have found a block.