I don't feel that the incorporation of elemental effects into melee attacks have been properly thought out so I wanted to try to put together an alternate list of effects. These apply when making a melee attack (unarmed via the elemental strike adept power or [Element] Aura spell, or armed via the [Element] Aura spell). When being attacked and under effects of the [Element] Aura spell, the attacker resists damage as normal. Additionally, the existing published secondary effects are not affected, unless otherwise noted.

As a starting point, I am using +1 DV resisted by half impact. Damage may or may not be converted to physical or stun. (Note that it seems strange that a higher force aura does not make your melee strikes more effective ... aside from the secondary effects.)

So, First thoughts:

• Acid: +1 DV, Physical Damage. Resisted by Half Impact (round up) + chemical protection armor upgrade rating. With Acid Aura, use the Force of the spell for the Acid damage rating of the secondary effect. For Elemental Strike use half the DV?
• Blast: +1 DV, Physical Damage. Resisted by Half Impact (round up). New secondary effect: Reduce target's body by 2 when determining knockdown.
• Cold: +1 DV, Physical Damage. Resisted by Half Impact (round up) + insulation armor upgrade rating.
• Electricity: +0 DV, Stun Damage, Resisted by Half Impact (round up) + nonconductive armor upgrade rating. Secondary effect still screws you over.
• Fire: +1 DV, Physical Damage. Resisted by Half Impact (round up) + fire resistance armor upgrade rating.
• Ice: See Cold. I don't foresee a bunch freezing the streets, but it would be nice to incorporate some sort of icy grapple at the location struck.
• Light (I punch you with lasers!): +1 DV, Physical Damage. Resisted by Half Impact (round up) + fire resistance armor upgrade rating. The glare modifier should probably last as long as the effect is sustained, not that it matters as flare compensation seems to be standard issue.
• Metal: +3 DV, Physical Damage. Resisted by Impact + 2.
• Sand: +1 DV, Physical Damage. Resisted by Half Impact (round up).
• Smoke: +1 DV, Physical Damage. Resisted by Half Impact (round up) + highest rating respiratory protection. Armor with a Chemical seal uses its full impact rating and negates the bonus to DV. Elemental Aura users should probably get a nice range of bonuses from being shrouded in smoke; all attacks against the user should suffer the heavy smoke visibility modifier. I would make this replace the struck target suffering the visibility modifier for 1 turn. I would also say that Smoke Aura users suffer penalties to infiltration and shadowing except in full darkness (just ignore the cloud of smoke walking by you... nothing to see here).
• Sound: +1 DV, Physical Damage. Resisted by Half Impact (round up). A cyber ear damper adds +2 to the resistance test. Should the nausea only kick in at Willpower x2?
• Water: +1 DV, Physical Damage. Resisted by Half Impact (round up). Revised secondary effect: Reduce target's body by 2 when determining knockdown. You still make the punched area wet. Ladies, don't wear white T-shirts...

Also, what do you think about allowing such users to make a touch only attack to convey part of the damage of the elemental attack? Maybe Force DV for Element Aura (could wind up being higher DV than a punch by the above calculations) and I don't know what for an adept Elemental Strike.

Do you think this makes things more balanced? I think it takes Sound down as the Elemental Strike/Elemental Aura of choice, but I don't think they are all on even footing.

Light should be resisted not with Fire, but with the Radiation Shield armor modification(arsenal page 50). It specifically protects against laser attacks.

Ice should maybe steal the Binding power's description (with a lesser test/action to get out), or keep the slip test - you pick whether you're freezing a single target or spreading it over an area when you declare the attack.

Electricity needs the potential to do Physical damage. It's something it's needed for a while. Not getting a damage bonus but being able to choose what kind of damage it is seems fair. I'd also say that if you soak the attack entirely, you don't have to make the Twitch Test.

Acid damage is holy shit good, so chemical protection should flat out reduce the DV of the recurring-each-round-damage. Not reduce the damage of the initial attack. If you get hit by a DV8 acid attack, you have 8 more turns of 8dv continuing to eat at you. With this change(lets say using chemical resist 4), you would get resist by an 8dv acid attack(with +4 to the soak), an then reduce the recurring damage to 4dv for 4 turns.

Sand is lackluster and needs to be better: give it an Accident test vs complex machinery. Unlike other elements, it doesn't have a secondary effect or any better dv/ap to make up for it.

Metal: metal needs help. The +armor penalty needs to go away entirely. It has no good secondary effect, and doesn't get half armor like other effects. Its bonus should just be more damage with no downside. As is, its objectively the worst. If you're houseruling it anyway, make it worth considering using. I'm not sure what the BEST solution is, but its shit as is.

Sound: Nausea is hella broken. Make it give Disorientation upon hit(no test, its a core book penalty that's basically -2 penalty), upgrade it to Nausea if you go over double willpower, and cut the duration down to measure in Combat rounds. Even long-lasting elemental damage effects like Fire and Acid don't last THAT long. 10 minutes stock is bullshit.

Blast: A-ok. The autoknockdown potential on the stock blast element is super dumb. A nifty secondary effect could be moving your target a meter per net hit on the attack, just like the Herding maneuver. You don't just knock people down, you knock them back.
Water: Same. Knockdown change is good. It should get the same Accident Test thing that revised Sand should, but vs sensitive electronics.

The thing that stood out to me is every element except metal, sand, water, and blast are 1/2 impact + some protection. Metal isn't half impact, so adding the +2 on top of that seems a bit harsh. Sand, water, and blast don't have any special protections, and blast has a useful secondary benefit. It looks like most powers that have a special protection associated with them also have a useful secondary effect (except cold, so ice is simply better), which helps balance things a bit.