SEO scope for multiple domains hosting on the same IP address

Search engines care about content of the web site and not IP addresses. Period. End of story.

Now, if your IP address or domain name is a known spammer; different story.

If you can create high quality sites, provide great user experience, and take care not to violate any of Google's webmaster guidelines, there is no problem with having multiple sites on a shared host.

With that being said, your sites sound like they could be spammy. You sound like you are at risk of violating the policy against doorway pages. The example domains you give are keyword rich. If those sites each have little content and funnel users to a main site, then Google is not going to be happy with you.

When you have many domains, you also have to be careful not to create a network of sites that looks like it is designed only to link to each other. Google has a strict policy against link schemes. You probably don't want to link from each of your domains to every other. You only want to link when the links make sense for users. See: Google’s Matt Cutts Says It Is Okay To Link Your Sites Together But In Moderation

If Google determines that your domains violate the webmaster guidelines in any way, they may penalize all your sites. Having all your sites hosted on the same IP address is one way that Google could identify all your sites, however it isn't the only way. Google might also identify your sites by other attributes they may have in common:

• Domain name registrations
• Analytics id
• Advertising accounts
• Affiliate codes
• Search Console account
• Software or modules installed
• Look and feel
• Creation date
• Link profile
• Writing style
• URL structure