I prefer bigger line spacing, as done in example 1 and 4. The word spacing in example 5 is too much imho.
On a computer I prefer reading sans-serif fonts, so out of all of these I like example 1 the most, even though, in printed text I think example 4 would be better.
Keep the SBD btw. 0.02 SBD is … well … I see what you're trying. This way you can limit the payout to 101 answers :-)