1. Balmung. If you're in the US, you'll need to try in the small hours of the morning to get in.
2. Classes have a primary stat, MND for healers. Although investing in PIE can increase your MP, this is not recommended unless you fully understand the stat weights and consequences of choosing an alternative distribution.
3. CNJ/WHM is nice. It's the most straightforward, direct healer and gets a good toolkit early on. Scholar, the alternative, is a pet healing class with a number of shields and mitigation abilities (But it is a pain as you're DPS for the first 30 levels, and don't get Leeches until level 40. Esuna, in contrast, is level 18). On either healer, expect to take heat if you don't have swiftcast by the time you hit level 50, as it's essential for battle rezzing.