Im wondering if I should incorporate multiple keywords in my incoming links. i.e. cincinnati roofing contractors or replacement windows, roofing contractors, siding, cincinnati ohio
I'd suggest that you use whichever keyword your landing page is optimized for. It doesn't matter long or short.
Use multiple keywords that related with your site as anchor text. Don't just use one, it looks unnatural.
My suggestion is that for: replacement windows, roofing contractors, siding, cincinnati ohio you should break it into 4 different backlinks. One for each keywords. And I agree with multimastery, make sure that keywords match the keywords in your website.
I would go with cincinnati roofing contractors. it looks more natural than replacement windows, roofing contractors, siding, cincinnati ohio.. isn't latter called keyword stuffing?
Its better to use multiple keywords in backlinks; however they will be well- researched. Use can use Google keyword research tool to check the prominence of keyword. Try to optimize your site for most prominent key phrase first. Your keyword prominency order is : Siding > replacement windows > roofing contractors> cincinnati ohio> cincinnati roofing contractors