What you describe sounds right for what you have. You'll definitely want to go to a charger with built in balancing and the separate power vs balance leads to connect for higher charge rates. Balance leads really aren't meant to handle 7 amps.
You can be off by 0.5 v/cell (highest pack to lowest pack) and shouldn't have a problem paralleling. Resistance of the wire and battery internal resistance will keep the current down as the packs equalize.