Yup in the beginning, for me it did, make sure to have the same directories , if your changing the names of the directories, urls etc , make sure to use a redirect.
It shouldn't make any difference as long as you don't change your domain name.
Google crawls you domain name IP NOT your ISP's server IP so it shouldn't make any difference. If you were really unlucky Google/Yahoo may try to crawl your website as the domain is being transfered over then you may lose some site rankings because they think your website no longer exists.
It's heighly unlikely you'll get crawled the day you transfer
Shouldn't hurt you, unless your engaging in some serious interlinking with other sites on the new c block.
As the others said, just make sure that there is no downtime, and the dir structure remains intact.
I moved my search marketing info site over to another server. the DNS propigated through lightning quick and Google spidered a page that did not even exist and I was still ranking at #6 for search engine marketing. that is mostly because linkage data, but you can switch hosts without seeing too much loss.
Changing the provider may hurt the ranking only in certain specific cases.
Some German webmasters complied that their English language sites were not treated well by Google, unless they were moved on a new host with IP resolving to UK or US.
In this respect, saving 10 bucks by moving your content on a server placed somewhere in the Central Africa may not be the best idea.
Similarly, server with 50% uptime will not do either.