Most of my videos are animations under 30 minutes, so I can afford to use lower bitrates than the default. The only way to know for sure is to experiment. When I still had my 1GB Kingston, I had to use even lower bitrates around 192 and I still got decent quality from that (although those were from an older version of BatchDPG). As for the number of passes, I recommend 2-pass encoding for low bitrates, but I find that I can do without the second pass when I use a better bitrate about 210. Again, it's all down to your own preferences, source videos and experimentation.
Additionally, I use the Lanczos resizer in all of my encodings.
Additionally, I use the Lanczos resizer in all of my encodings.