The negative Floof score really comes from earlier times when the system had a "bite" option as well, some users could/would make their way onto the forum and make posts or replies that more disliked than liked, leading them to a negative karma/floof instead. In many cases it was understandable, but in some cases it happened to users that really didn't do much wrong, and some even got targeted by group of users to have their floof go down on a wider scale, even into the negatives due to pity drama. We decided to remove the bite option on profiles and instead focus on the positives since it brought a more positive feel to the forum on the wider scale. I do believe what was done there really were for the better, but some old profiles still might lay around with negative karma.
Regarding high floof count and low post count, truth be told, if you make a popular modification to a game and only come to make update posts or add certain replies or material that you made yourself, as a whole your posts are bound to get more +rep quicker since it's all about what kind of nature the post itself has. Even though it doesn't stop anyone, it's not as likely to get nuzzled when you tell users opinions that might go against theirs, telling users common information around the board, or just making casual every day chatter. So even though it's true that more posts will give you more recognition and it's more likely that users will nuzzle you, it's just as much if not more about what kind of posts you make rather the amount. If you want to get nuzzles quickly a tip would be to make an interesting or fun mod and post about it, don't think my karma has ever grown so much as the time I made the initial posts/update posts about FeralCity.
Another way really is if you're a very positive and happy user that replies to a lot of content posted by other users, of course well written feedback or just appreciation is welcome in many peoples eyes, giving a nuzzle back is probably a common thing to do when people see this. The nuzzle function/karma does have a lot to do with what people want to see and hear before anything else which is completely reasonable when you think about it.
The post counts for Raz and Tigg is really a fun/derp sort of thing, and since no greater harm as been done it has just been there/like that for years.