berryracer
To work SVP x64 need all it's parts in x64 too: splitter, decoder, ffdShow, avisynth, SVP libraries, renderer and player.
Avisynth x64 is still unstable and alfa state.
SVP libraries x64 are absent.
If you want you may search the answers of your questions 1, 2, 3 yourself.
I got an error
Where is last launch log?
And show AVS-script please.
We have two ways to resolve lack of memory issue:
1. to combine all x64 versions of soft together, SVP libraries recompile to x64, test and debug it many-many days and nights - hard way
2. to change some settings in SVP to lesser memory use - simple way