I must say, although i'll be paying closer attention this year, the korean matches dont make a great spectacle on tv, do they? It reminds me of when I was young watching Barnet. In one game we beat Blackpool 7-0. In my mind we'd had about 50 chances in the game. Then I watched a video of the match, and discovered that most of these 'chances' were simply crosses into the box that looked far better from my position in the stadium then they actually were!
When football is good (like the EPL) then its very much suited for tv. But when its bad (and we've got to face facts, the k league is simply dire at times!) then tv isnt a great medium for it. I imagine seeing empty stadiums does little to impress people either.
I think there needs to be a new rule in the k-league, where the chaebols get together and create a centralised 'star player' fund. Each team gets an equal amount to spend on a player that must be a 'big name'; someone like Pires, Crespo etc who is past their best but still good enough for the kleague. Then you'd see tv coverage grow, interest grow, and ultimately attendances grow. But thats not going to happen unless the k league can take an element of the 'EPL experience' and sell it to the people of korea.
Australia has a similar system to what you are suggesting called the Marquee system. In Australia there is a salary cap so it's an important rule to make sure teams can add Star power if they want. In Korea the chaebols already have a lot of cash and the means to recruit name players if they want and I am sure one of them will stump up the cash to bring Park Ji Sung back when he is finished at United. The new Indian league is using that system too and it's a good interest boost for people that aren't following the league but for those already following they generally just prefer to see their team win matches. I think some teams have just stopped worrying so much about chasing the people that aren't watching them and instead focus on the fans they have and use the spot to keep fan favourites at the club for longer when there is overseas interest.
The nature of those "marquee" overseas players is it's a very brief love affair, thy are interesting at first but the effect wares of quick and you have to build up the profile of your players who will be there for 3 or more seasons to build up any affinity for the team.
As to the quality of the league it's a bit of a mish mash, overall it's probably better than the A league but it is much less even. When I watch the A league I know it well enough to know which games are likely to be good and which ones will be duds..... similar to the EPL I'm not going to watch Stoke vs Blackburn unless I'm bored but will make sure I'm watching Man City vs Man utd.
In Korea I am not as familiar with the teams or players so I could be watching Stoke vs Blackburn for all I know and a lot of the drama is lost on me because I don't know the back story.
From the little I have seen for a neutral I have learnt the following rules.
Pohang at home is worth a watch because there is usually a decent atmosphere in their stadium which does matter.
Seoul vs Suwon... watch it!
ACL games involving Chinese/West Asian opposition...Avoid, Avoid Avoid! There are some great moments (like the Suwon vs Qatar cheats game) but a lot of my worst experiences have been watching these games. It might improve a bit as a spectacle with the Chinese teams adding some star power now but they are the kings of Anti football.