My mistake about the steampunk thing. I was thinking of a setting more like FFVI, but I guess even that story had some genetic engineering type stuff going on.
You seem to want to give players the abilities to recharge powers with healing surges. Some people have suggested adding a bonus to certain rolls by spending healing surges is more balanced. Although adding a small bonus can be very beneficial, I don't think it is cinematic enough to make the players feel very powerful. I don't think that recharging used abilities (as you suggested) is too imbalanced, but I have an idea that could work.
Write up a list of powers that the players can take which are very strong but require healing surges, action points or hit points to use. This is a bit more fun than just recharging the powers they already have (using the same power a dozen times can get boring).
As a starting point, one of these powers can be an at-will minor action that recharges an encounter power at the cost of a healing surge, and another is an at-will minor action that recharges a daily power at the cost of two healing surges. The latter can only be used if you took a short rest since you last used a daily.
Most of these powers will be at will or encounter powers since they are limited by healing surges rather than rests. Also, make some powers work best with wizards and other classes that get low HP and healing surges to help balance the powers for these classes.
I suggest granting the powers to the characters at first level, and every 2 levels afterward (3,5,7...). You can limit some of them to paragon and epic tier, and you might allow them to purchase extra such powers as feats.
I don't think you need to worry about balance issues too much. Your campaign is going to be a little extreme if everyone is steam punk, so just use stronger monsters to compensate. Just make sure the steam punk abilities are balanced compared to each other, and that they don't completely overshadow the class features.
Here are a couple of sample powers.
Flames of wrath
At-Will, No action
Cost: 1 healing surge
Effect: Use this power when you hit with an ability that has the fire keyword. All enemies hit by the effect gain ongoing fire damage 5 (save ends). If the spell already causes ongoing fire damage, instead add 5 to the ongoing damage to targets that were hit.
Inhuman strength
At-Will, No action
Cost: Action point, 1 Healing surge
Effect: Use this power when you hit an enemy with a melee attack that has the weapon keyword. Add 4[W] to the attack damage.