if by anime edits you mean editing a footage (cutting, sync timing and such) then you will have a much better performance if you do this in Premiere. If you mean adjusting keyframes, applying effects and composite more layers then go on. As for the RAM preview issue, we need more information:
1. Exact number OS and AE version
2. Did it ever work or is this a new issue?
3. Show a screenshot of your full Ae interface visible. Show the preview panel too.