I sort of agree with you ( see my time stop in a feat, feat, or my comand in a feat, or bull's strength in a feat etc) but You also have to realize that some feats are always on, while some can be used conintuously, or at any given time.

Interpose is basically a suped up version of shield other, and is going to get and at levle 20 is going to have 7+Wis modifer times it can be used> and that is the power level im working towards, maybe not as striaght up as powerful as a spell, they ability to be used more oftne or just on at any time makes up for the fact. I do not want these feast taking the fighter from 'tier' 5 to 'tier' 2 because really.. those top 2 'tier's are just a little too crazy.

SO while they should be as strong as spells, there is now way I cna justify giving a fighter a feat that is as powerful as say.. Gate or shapechange

Since verybody gets feats, thats another reason why some feast are BaB dependant, becuase hey MR caster you alreayd have things that are more powerful than what any mundane class can do, so NO you do not get the super cool feats.