>right now I am planning to get a new reseller domain at
>hostgator and set up blogbomb there.
>
>I am thinking of useing a domain name with the word hub in
>it, something short and general so I can use this site to
>feed other sites. Does that make sence?

Only if it helps you remember the domain as the word "hub" has no signifigance to the system.

>initially these will be to drive traffic in the weight loss,
>fitness, health to an established weight loss blog where I
>have monitized with CPA now but will add Amazon and I have
>been working on building a list. I also plan to offer some
>of my own products there.
>
>does this sound like a good way to get started?

I agree.

>Later I plan to add some gold sites in the same field with
>targeting variation like natural weight loss, fitness niched
>to tai chi, yoga and like that.
>
>When I start running a different niche area like say cars
>related, should I start that with a new reseller account and
>new domain?

There's too many variables to give a "one size fits all" type response. In theory, I wouldn't dedicate one reseller account to cars, another to yoga, another to tai chi. Instead, it would be better to spread each out across multiple hosts to get a little benefit from cross linking similar sites.

>Can 1 installation of blogbomb send out feeds for totally
>different niches or would it be best to have a new
>installation for each niche area?

Yes and no. One instance of BlogBomb can "broadcast" RSS pheeds, but each domain will need a "receiver" to translate the RSS to html. Make use of a skeleton directory available in WHM to automatically install Blogbomb each time a new domain is created.