Have you called the hosting company? They may say that you need to switch to a Linux box, and they migrate everything over for you. Or maybe they can help you get your redirects in place on their end.

If not done correctly can take your main site down, so it can be done but they need to know what they are doing.

Absolutely. This gets you a thumbs up. If you are not connected to the main site, then you can take some risks and have some fun, and conduct SEO experiments without harming the enterprise site.

"But then you can indeed use some rather grey SEO tactics towards these buffer micro sites if you would want to... without being at risk of bringing the entire house down."

The reason why would be for multiple 1st page positions in the serps for the same keyword phrases. Most sites are not lucky enough to get rewarded with host crowding positions (your same domain ranking multiple times on the first page) but if you have microsites that you are able to get ranked now you have several first page positions.

If you are addressing different targets, this can be accomplished probably easier with your main, established already trusted site.

Google is addressing exact match domains as a ranking factor for exact reason. Microsites are spammy and grey hat and outside of Google's webmaster guidelines if addressing the same targets.

The noindex,follow tag on paginated pages will not compromise your sites integrity with Google. I think it's important to look at your site as a whole and divide the number of all pages by paginated pages.  If the ratio is above 10%, I would be concerned that the site may appear to be more of a directory and it definitely would make sense to noindex the site. Also, there are paginated pages with just a bunch of links and other paginated pages with a lot more data surrounding the links. The fact that others are ranking higher probably have more to do with overall site content and PR.