As far as your supplemental index is concerned, this is the site that I used to calculate your percentages
Supplemental Index Ratio Calculator . It also gives you tips on how to correct it.
To your second question, I do not think this is wise on many different stand points. Let me just elaborate on a few of them.
1. By putting bits and pieces of your site on multiple servers, you will create different load times of your pages due to the number of hops to the different servers. All it takes is one page not to load, or to load slowly, and your visitor is leaving.
2. You will create confusion amongst your visitors because it will be jumping to many different sites and back again.
3. Due to linking back and forth from site to site, it would be classified as reciprocal links in Google, not totally helping your
PR.
4. Each domain would be its own site. This means you would have to get backlinks to establish
PR for every site.
5. You would be paying numerous hosting companies to host what is in essence 1 site.
If you must host parts of your site on different servers in that country for that particular country, then I would create stand alone sites that have relevant and maybe even close to the same content, but not duplicate content, for each country. Then I would put a one way link from the country's page back to your main site. This would increase your page rank because of the one way links and since you run the sites, you can control what anchor text is used in that link. As your country sites gain
PR, the more link juice will be passed to your main site. But I would not do that now. I would fix the issues with your one site and only add the other sites once the first site was running ok. But I am still not sure that I would host them in the different countries, and if for no other reason, calculating the currency exchange rate.
As it stands right now, I would put each country in a subdirectory on your main domain. I would use the subdomains for the different languages for your site.
For everyone that is thinking right now that using subdomains for the different languages is going to cause a duplicate content issue,
please follow this link .
I hope I did not confuse you with my answer. If I did, please let me know and I will try to clarify.