1.Fistweaving is like Priest's smite healing. It's not necessary whatsoever. In fact, most of the time you'll want to heal normally. It is NOT free. Idk who would describe it as such. Lol.
2. Our mana is pretty decent compared to other healers. I think we even have a slight advantage over certain other classes, but with starter raid gear of course you'll have a few issues keeping mana up. It's normal. Just stack spirit. Right now I'm running with around 8k unbuffed and I'm pretty good with most fights, as long as people aren't messing up and doing things they're not supposed to be.
3. Mess around with all of them. I usually go for Zen Sphere for fights where you'll be grouped up. The other 2 aren't really too effective, since you'd probably want to prioritize Uplift over all of them when people are spread out.
4. I think it's better for us to heal. I guess if you were OOM and about to receive some heavy magic damage from a raid boss, you'd want to pop it. Otherwise, just stick to healing. Some fights can get pretty intense toward the end and it's just better to keep helping the other heals.
If you have any other questions, feel free to PM me. I'll try to get back to you ASAP. Again, good luck!!