How the single virtual host of Apache can see the AMF environment variable in httpd.conf ?

just put in the main configuration of Apache this command: PerlOptions +Parent 

Which platforms AMF supported ?

In the theory all platform support Apache and Mod_Perl but if you want have more informations go to CPAN test report

If someone is using an iPad or some other type of tablet, they should be able to view the normal version of the site since they have a larger screen than actual mobile devices do.  AMFSwitcher can do this ?

Yes, in httpd.conf file you must set this option:

PerlSetEnv ForceTabletAsFullBrowser true

Do you think to support GINX ?

Not yet

AMFImageRendering support transparency images ?

Yes

AMFImageRendering support animated gif ?

Yes. From the v3.30 or newer the AMF support animated gif ?

AMFWebService support DEFLATE mode ?

Yes. From the v3.30 or newer DEFLATE mode is supporte.