Google's take is you're not supposed to do it.Also,

a) make sure the domains are private registration so no one knows who owns the sites

b) put about 2000 words per page on the site, you can get away with a two page site just make sure both pages have tons of unique content

c) link to your site from the web and let Google find the site on it's own, don't submit it to Google's ADD URL tool - some claim that doing so tells Google that this is a new site, if Google finds it on it's own it doesn't make that determination (again can't be proven 100%)

d) this strategy only sometimes works for some reason, don't count on them all ranking.

It doesn't matter, because in Google Webmaster Tools you can geo-target directories for specific countries, so there is no need for different TLD's for different regions. It seems to work well.

Also, Google is smart enough to know that if a section is in German it should be shown in Google.de, if a section is in French it will be shown in Google.fr - it is the English sections that you definitely need to point Google in the right directions with.

Load time is absolutely a consideration in rankings, go into you google webmaster tools account and you can see your site performance and how your load time compares to other sites on the web. Images are just one aspect of why your page load times could be considered slow but it is a factor. Get the yslow extension for firefox and that will give you some suggestions about what other changes you can make on the site to reduce load times.

I would play around with optimizing your images in photoshop and see what percentage decrease you can get away with without noticing a difference. If all of your images are roughly the same quality you can do a batch in photoshop, which is basically making an action first, for example saying shrink all images by 15% and then batch all of the images in the image folder and photoshop will shrink them all in one shot.

tutorial: http://www.pagecurve.com/tutorial.php?id=5_0_1_0

both are important for SEO - the filename in the URL should match up with your title tag. all filenames should be unique. for example

www.coolsite.com/kids-toys/blue-schwinn-bike

not

www.coolsite.com/kids-toys/blue-schwinn-bike/index.php

this latter example would cause you to wind up with Google seeing every page with the same filename index.php