1. You can edit your own posts to circumvent the character limit
2. You come across as an intelligent player who does want to improve. Unfortunately there indeed will be times when your party pigeonholes you by playing poorly, forcing you to sit on your GCDs in case they all derp horribly and try to wipe you. It's hard to be a shining star as a healer when your party holds you back. At least in alliance raids you can let the bad ones die and keep going.
3. People keep saying that healer DPS is nice, but not required; I would certainly consider it a requirement to DPS whenever reasonable to do so. As a new player I remember getting over my initial hesitation to use CS in parties at all, and again learning how to do it on WHM. It's a process, and it's not possible to be truly good at the healer role in this game until a player learns ALL aspects of it.