It should be possible to create a substantially more professional look just using CSS and HTML. This does not conflict with 'minimalist' as some people seem to think; in fact a professional look is usually minimalist. I would describe the current look as minimalist and endearingly klunky.
Facebook and G+ like buttons should be considered - they are standard and I assume quite effective. The supercookie tracking is definitely a concern, and if you want to go there it is probably worthwhile checking you will not alienate the present readership. I would support it though.
You may also want to consider the various ponds available to you. I know nothing about kernel programming, and am a free software / web collaboration enthousiast (i.e. a small fish from a bigger pond). I appreciate the occasional kernel article if there is an interesting angle to C programming, but in general I appreciate other articles just as much if not more. You could (further) experiment with articles on various topics (much as you already do). You probably have statistics on page hits already, however, they might mostly reflect on your current paying readership rather than the prospective readership lurking out there. Again, 'like' buttons could help you there if they allow new visitors a bit deeper access than non-subscribers.