Nameservers, DNS, Multi domain & domain mapping

Hi

Am a newbie to WP and learning fast with painful experiences of perpetual "redirect loops" in my first attempts.

Have now done a fresh install & just building my network template before setting up the proposed multisites with mapping.

Experience has shown how just 1 wrong click in this set up can prove disastrous and as a relative non techie, I am asking these questions now before embarking on the activation of the next stage.

Background.

1. Intention is to run a network of marketing sites for 1 business which has various different specialist skills.
2. Have secured .com domains for all the various skills (eg.skill1.com, skill2.com etc) and will drive traffic etc with offsite promos for these "brands"
3. Idea is to construct 1 principle site (domain.com) and have set up multisite as sub-domain structure.
4. Domain.com is set up as a portfolio site with features / links to all the brand sites - Skill1 etc, all with separate content etc.
5. Brand sites are set up as "skill1.domain.com", "skill2.domain.com"
6. Hostgator VPS set up with DNS for Domain.com managed at Hostgator
7. All brand domains are held at GoDaddy.

Questions ref the Brand domains

a. Should I set brand domain ns1 & ns2 nameservers at GoDaddy to point at Hostgator IP address for Domain.com
b. Should I also set their "A" record "@" to do the same ??

Question ref the DNS set up at Hostgator

a. Currently have wildcard set for *domain.com
b. Should I now set wildcards for all Brand domains here too

Above is currently how it is set, but in view of potential for repeat of the redirect loop nightmare, dare not yet test.

Hope you can clarify. Thanks