SE Startegy for relate Domains with redirect

We have two domains (public /services) that SEs should recognize as one

[Steppenwolf]

We are a young company producing and hosting multimedia content for others. To seperate development I split our website in two (three) domains.
One of them (.info) is used to provide the services (which are linked by our customers or directly integrated into their sites via iFrame using a link with 3-6 parameters)
The second (.de) is used as our public homepage, describing the company, offering services ... (Online for 4-5 month)
A third one (.com) does a 301 redirect to the english version of the .de Page.

So far we have a PR of 0 and I just started to look for ways to change that. There are a lot of useful posts especially here on WebmasterWorld, but before starting anything, I'd like to find out if my setup is wrong.

We are likely to get many inbound links to the service pages of the .info domain. The root of this domain is a 301 redirect to .de (was 302 redirect till yesterday). We want to get our .de page popular.
What is the best strategy to follow to benefit from the links to .info?
Should I relocate all pages to .de and redirect all requests there? Does it have an advantage to switch to .com with all pages since we are operating europe wide?
.de links to many samples on .info - could that be a crosslinking issue?

Any thoughts/comments are welcome. If you need additional information, please tell me.