If you wanted to engage in the world's least interesting scavenger hunt and are willing to spend a perk on it, getting all the skill books and skill bobbleheads puts you at a baseline of 60 for each skill. There are 15 skills, so if you want to max out everything you will need 600 skill points from other sources. If you take the "Almost Perfect" perk at level 30 (because the other level 30 perk is broken, and has the effect "Kills the player when health is reduced to 20" on normal or higher difficulty) you will get +27 to all your skills (+30 if you wait and collect the SPECIAL bobbleheads). Which means you will only need 195 skill points over 30 levels to max out all the skills. An intelligence of 1 will give you 11 skill points per level, which is more than enough. There are no intelligence checks or similar in Fo3 so a Lone Wanderer who is as unintelligent as the game allows can still easily end up as good at everything as anyone can be.