But a load of skills like you suggest would probably lead to a system where there would be a skillpoints imbalance (more skills, thus you at least don't get less skillpoints and probably more, which in turn helps create uber character, since the extra skills are more flavor than definitively useful).
With a skill point distribution ratio that changes the higher the skill becomes this can be avoided.
Getting the tagged skills to 100 is easy, getting three additional skills to 100 is going to consume skill points like crazy.
Best thing to do with untagged skills would be to just raise them to 50 or 75.
And hell, it's all about choice, you want to focus your skill points on the best skills to create an über character? (Not directed directly at you.)
Then do so, I'm going to specialize my character and at least I now have the option to do so.
And yes some of these skills could be from the stats, thats why I said that the stats would greatly influence them.
With a 6 END and 5 AGI character you will have 55 in Swimming and Atheletics, now, you "can" raise these skills to become better, but it's going to take skill points.
So it's not like they'd start out at 13-21 like the rest of the skills.