Proxy location relevance

Hi.

I use US dedicated private proxies for everything. My question is has anyone seen any different in account activation or SEO efforts by not using US proxies?

I'm looking to use proxies from other countries to cut costs. But what I'll be using them for is indexing via google and social account creation.

Social account creation - any proxies are ok as long as proxies are not spammed.
Same comes to google.
US proxies are not better in any way.
I make x-xx thousand accounts a month on various social sites and i dont use US proxies - all is ok.