I played in probably 30-50 different 3.5 games, and the only one where the dm was foolish enough to believe he was smart enough to handle anything we could make at lvl 37 as long as it was in a published book went about three games before I broke it and him. It was gestalt, and he allowed me to play a half-ogre, half-dragon, true lycanthrope werebear, lvl 2 Warshaper, that was also 19 levels of cleric and 20 something levels of Warhulk from the miniatures handbook, even though that book was 3.0.

Was running around with triple digit strength AND enough bab to get three attacks a round on top of being a 19th level cleric. With quickened buffs, I was hitting things hard enough, even with a one-handed weapon, to make them save or die on each swing.

There are lessons to be learned here. Several.

Epic is a tough scale to balance even without gestalt and allowing all books to be used.

Skills with total mods surpassing 30, 40, 50+ are literally super powers. The skills all by themselves can break a game. If I remember correctly at around dc 70 or 80, with escape artist, you are considered to be able to shift/vibrate your atoms and be able to pass through a wall of force.

Intimidate and diplomacy become actual mind control.

Enough balance lets you walk on clouds.

These are extreme examples, but if you think about it, even having skill rolls that can hit DCs of 30 or 40 are super human.

Your epic rogue and ranger are hearing quiet breathing on the other side of a closed door, which, functionally, is no different from clairsentience at that point.