Exactly, getting all the perks in a single playthrough would mess with the game′s replayability

Just make the level cap high enough that you can't reach the level cap under normal game play (IE, not heavily grinding respawns). The drive to explore and complete every area in the game goes WAY down when the stuff you kill doesn't give you experience, especially as your need for gear and cash starts to disappear.

I only remember being able to max one or two skills in the first games if I focused on them and were tagged. Fallout 2 had a 99 level cap but it would take a mind numbingly loooong to to get that high.

After all DLC's were loaded you could get 29 standard perks in FO3 and 25 standard perks in FONV.

As for the chart. The first row shows the SPECIAL attributes and their associated Pipboy icons. The Intense Training perk is not on the first row. The perks started on the second row.

The at launch max level has got to higher than the FO3&FONV or it needs to take longer to level up because hitting the max level too early on can be disappointing and break player immersion.

I just hope it's impossible to max everything. While max lvl character with max skills can be fun, once you get there, having completed pretty much every quest and enemy in the game leaves little excitement. Part of the joy of the first couple games was having to specialize as you couldn't be perfect at anything, making multiple playthroughs required to see it all.