Imperfect, 100% of the Time

Conkeror's block-content-focus-change module watches for focus events, and permits or blocks them based on how recently the user hit a key or clicked the mouse. If the focus event happened within 20 milliseconds (by default) of a keypress or mouse click, it is assumed that the event resulted from that input event, and allowed to happen. Otherwise the newly focused element is immediately unfocused. To enable this mode, put this in your rc:

require("block-content-focus-change.js");

I hinted that the 20 millisecond duration could be configured. Here is how you could change it if Conkeror seems to be blocking focuses from your clicks (happens on slower computers):

block_content_focus_change_duration = 40;