I don't think so. Just make sure your site is already uploaded to the new host before making your DNS changes, that way, there is no down time.
As long as you keep the same domain name and upload everything on the old server to the new one, the search engines won't even know that the host has changed. And make sure that the down time is reduce to the minimum.
your PR wouldnt be affected since the domain name is not changed.as others have rightly said make sure downtime is zero.
Changing host doesn't have an effect. Even being down for a time has no effect in my experience. Although I'm not certain, speed of access can have an effect so if you change hosts, change for one that is at least as fast as your old one.
no effect...unless ur server doesn't come out to be supporting asp, php, mode rewrite or whatever u had with previous server in accordance with ur site
Sometimes, this actually can affect your ranking. This is especially true for servers who's IP addresses have been blocked or disregarded by Google. If it is something you are truly worried about, ask your Web host for sample Websites hosted from the same server as the one you will be placed on - then, look and see how these other sites rank in Google. Hope this info helps.
If your targeting regional seraches like (Eu) or (ca) traffic for example, or (China) then youll do best to have a server ip located in that country.
No it will have no effect whatsoever. The information that you upload will be the same whoever hosts it.