Feats that provide a bonus to a d20 roll have no business scaling. On initiative it isn't so bad because there's not really a set RNG to stick to, but I'm still opposed to scaling feat bonuses on that sort of thing in general. For damage or hp or whatever, it's fine and probably necessary. But a bonus to a d20 roll means as much at level 1 as it does at level 20. Scaling comes primarily with level, dependent on class, feats and other options exist to give yourself an advantage on that roll relative to others of the same level/skill. Consider it this way: If you have two Fighters at level 1, and one has this feat, he has a 10% advantage. At level 20, the one with this feat has a 40% advantage. Compared to the status quo, where you have a 20% advantage regardless. There is no need to have that advantage to scale up. It's not like damage, where a +2 bonus to damage is worthless by level 20 so it needs to scale. A bonus on a d20 roll maintains its effectiveness no matter what.
They don't need it.I included wisdom mostly for the non-melee based full-casters
Bad assumptions. The Cleric will have full BAB from Divine Power, and the Cleric will not have as much invested in Str or Con as the Fighter, he will use spells to supplement those and have a higher wisdom. The Fighter's dex is not going to keep up with that.My goal was to have something in the Initiative calculation for (almost) everyone, so that while the high-level rogue or ranger might still have a signifcant advantage over a wizard, that same high-level wizard wouldn't be stuck waiting his turn behind 15 level-1 goblins.
Assuming a melee-based cleric has to spend the same values in Str and Con that a fighter does, then it seems like the fighter can put any extra points in Dex while the cleric dumps them in Wis, and the fighter still gets a better boost from his higher BAB.
It depends heavily on how you are fixing the cleric. We have no idea what your other houserules are, and given the context of the normal rules, you are just giving another advantage to a class that does not need it.If you are measuring this against the classes as they exist purely in the RAW, then there are so many other ways for the cleric to overwhelm a fighter it hardly seems worth mentioning. If you can get the cleric class balanced with the fighter, then I don't see why a melee-focused cleric should have any less of a shot at winning initiative.