IIS 7.5 URL Rewrite Module & Redirects - redirect

Question

My company is embarking on a large website redirection at the moment and I decided it would give us the perfect opportunity to make the URL's more user and google friendly.
To give you a brief outline of the situation, I am the SEO guy and I am dealing with an external developer in order to redirect the website without hurting the current rankings in Google. I don't have much experience regarding sharepoint hence why I would really appreciate any assistance in understanding and knowing if there is a work around to my situation.
The website is using IIS7.5, they recently installed the URL Rewrite Module in order to create more user friendly URL's. My question is, by creating a more user friendly URL, does this cause an additional redirect?
For example: if a user types in www.domain.com this permanently (301) redirects to www.domain.com/pages/home.aspx.The developer told me that in order to rewrite the URL to display something more friendly (like www.domain.com/home) this will have to cause another permanent redirect. So in essence the process will look like this:
REQUESTING: http:// www.domain.com
SERVER RESPONSE: HTTP /1.1 301 Redirect
1) Redirecting to: http:// www.domain.com/pages/home.aspx
SERVER RESPONSE: HTTP /1.1 301 Redirect
2) Redirecting to: http:// www.domain.com/home
SERVER RESPONSE: HTTP/1.1 200 OK
Is this how the URL Rewrite Module really works? I would have thought that it would not have to create another redirect in order to create a more user friendly URL?
My second problem is this.... The redirect is happening on the same server. So here is essentially the situation:
www.old-domain.com
www.dev-domain.com
www.new-domain.com
The old-domain needs to be redirected to the new domain so we ran a test in order to see if the HTTP status codes were correct before going ahead with the project. So the developer redirected the dev-domain to the new-domain and the redirects look like this: (The developers comments in italic below)
REQUESTING: http:// www.dev-domain.com
SERVER RESPONSE: HTTP/1.1 301 Moved Permanently
1) Redirecting to: http:// www.new-domain.com/
SERVER RESPONSE: HTTP/1.1 302 Redirect
2) Redirecting to: http:// www.dev-domain.com/Pages/home.aspx
SharePoint’s alternate access mappings causes this to happen and there is no way around this.
SERVER RESPONSE: HTTP/1.1 301 Moved Permanently
3) Redirecting to: http:// www.dev-domain.com/pages/home.aspx
SERVER RESPONSE: HTTP/1.1 301 Moved Permanently
4) Redirecting to: http:// www.new-domin.com/pages/home.aspx
SERVER RESPONSE: HTTP/1.1 200 OK
The developer states the reason for redirecting back to the dev-domain then back to the new-domain is because of SharePoint's alternate access mappings and there is no way around this. Is that entirely true?
Any assitance at all will be GREATLY appreciated!