The problem that i have with what you two are offering cadfan and Ghearus is that why should this type of feat be only usable for Rogues?
Because my feat is positioned around Combat Advantage, and Sneak attack penalties

Why not allow a Archer Ranger, or a Dex based fighter enjoy the benefits that a high Dex would offer?
Dex-based fighters are inherently nerfed as all of their powers key off of Strength. Archer Rangers *should* be disadvantaged in Melee combat; they are not built as front-line combatants, they are artillery.
Rogues, on the other hand, frequently need to be in the thick of things in order to be able to gain flanking so they can get Sneak Attacks. Allowing a Rogue to sacrifice some Sneak Attack damage for a higher precision attack, in my mind, seems like a very reasonable balance.
I think that my suggestion better allows for that. If you wish to use a short sword and have it hit with dex instead of Str, that's great, just prevent the damage associated with the feat and you have a well balanced feat.
I very strongly disagree; your feat is powerfully *unbalanced*, especially because it affects any Str-based power. For a few points of damage, all of your Strength-based powers can become more accurate, and you can potentially treat Strength as a dump stat. This is even more-so the case when you come to status-inflicting attacks where the status is more desirable than damage, and therefore accuracy is more desirable.
This is, based on my understanding, the reason why similar feats only affect a small subset of attacks, and only in certain situations.
Cheers,
Ghearus