I would like to be able to set the throttle control on the options page to 0 lines. I use MWP with heuristics turned off and all mail considered SPAM unless specifically allowed via the Friends or Filters lists. Reading 20 lines (the current minimum) takes extra time which is not required in this mode.

We are considering this, though do any of your filters seach the message body ? As setting the spam throttle to 0 lines would make these pointless.