The problem was clearly twofold
- skill list bloating all by itself is a pain because, as a player, you have to keep the whole list in mind when developing your character in order to avoid leaving out an important skill for your character concept, and as a GM, you run the risk of focusing on the skills you remember and ignoring the others when asking for skill checks.
- and skill list bloating without a corresponding increase in DP just means that characters are, on average, less and less proficient.
I think the first (and main) question you have to ask yourself as a GM is 'what is important in my game ?', and the second is 'how many skills am I comfortable with ?'. Think about special cases (combat styles, for instance - there might be dozens of different skills, but how many will a character actually develop ?), then make your list, keeping in mind that you might want a bit more detail for skills that are central to your game.
Then, adjust available DPs so that people need to either prioritise or be consistently subpar in everything - keeping in mind that RM integrates diminishing return in skill development, so depending on your game perspective, the 'subpar' statement might be more like 'not brilliant, but still quite good', and that a few skills (notably spell lists) have a different logic.
Everything else can be handled by style variations, skill focus, and background traits for everything you do not want (or do not need) to quantify because it is only for character colour and it will not be used in stress situations.
For instance, if a player says "my character plays the piano really well", then you have two options
- either make it a skill, but if you do that, you have a duty to ensure (as a GM) that this skill will be one of the focus of your game, taking the spotlight in a number of scenes and being key for a number of conflict situations.
- or you consider that this is a "background" skill, and do not need to quantify it beyond a "XXX plays the piano really well". It might be used for a couple if scenes because the character finds themselves in a situation where they can show off, and it might even give them brownie points with an NPC or two in the right circumstances, but it will not be used in a conflict situation.
And basically, you trim the skill list according to that logic.
The problem with a number of games (especially the more or less "generic" systems) is that, since they have no intrinsic focus, they provide you with a default skill list that aims at covering any game style - and they seldom tell you that trimming the skill list becomes your job as a GM, because only you know what kind of game you will be conducting. The additional drawback is that, since they have a default skill list that covers every possible case (and far too many for you, typically), they don't have additional mechanisms to handle the "no skill required" situation - and, as a GM, you have to come up with a mechanism all on your own (or pilfer it from another game system).