CC questions. Please help

[bagelmonkey]

I'm starting to consider CC as an option for the future, but have some questions I'm hoping someone can help with before I figure out what I'm going to do.

The background:
DD is 7 months old, BF, started BLW but not got that far yet.
Naps have always been a problem.
I did PUPD with her and it worked for a while and we had a little wind down routine and she would settle for decent naps probably 2 out of 3 times per day.
Then we moved house and she got more active and really resisted naps. They've just got progressively worse. If I try to wind her down she either cries or starts wriggling all over the place laughing. If I try PUPD she either starts rolling around playing in her cot or cries so I PU but doesn't stop crying until she's exhausted herself. I abandoned PUPD because she was essentially going to be crying herself to sleep on my arms, not settling herself. She will happily roll around in her cot for ages.
She gets so tired she falls asleep when I'm feeding her, but only for a v short time then wakes again.
At night she falls asleep when I'm feeding her and I can't see a way out of it because she's just too tired to do anything else.
She goes to sleep around 7ish. Sometimes wakes around 11, then again usually between 3-5. I can rarely get her to sleep past 5 or 6am. She used to feed very hungrily at night, but less so recently.
I wanted to try NCSS, but I can't keep her awake during evening feed.

Questions:
Can we use CC just for naps or do we need to use it for everything? ie is it all or nothing? If she napped better I think her nights would figure themselves out.
Does the same person need to keep going in until she's asleep? Can it be a different person for each session?

Thanks for your help.

I did CC with my DD when she was 11.5 months.
She had never been a great sleeper (up between 2-6 times a night for BF) and never napped for more than 10 mins or so during the day and had to be rocked to sleep in my (or DH) arms.
I started CC at bedime and the method I used was to let her cry 1 min, go in and resettle, leave her 2 min, resettle, 3 min... and so on.
The first night she was so cross that she actually broke the slats on her wooden cot by jumping up and down with rage. She still got up once that night for a Bf
The second night I did the same and she slept right through.
The third night, I just put her down and she didn't cry at all.
After a few days of her sleeping fine at bedtime, I started doing CC with naps and it took a couple of days again to work but after that, no problems.
I think if you do CC for naps only, you're as well doing it at night too as she will realise quickly that bed=sleep and will be able to resettle herself if she wakes.
When I did CC myself and DH took turns going into DD as it let her know that it didn't matter which parent came in, the result was going to be the same and she might as well go to sleep.
Good luck if you decide to try. I found it very distressing hearing DD cry but the results are very worth it and she's a much happier child now she is getting enough sleep!