Ways to increase 1H/2H/Archery damage in vanilla Skyrim:
- Base skill increase
- Root-level perks (5 perks for +100% damage from skill and material tier calcs for all aspects of each kill skill)
- Critical hits
- Smithing
- Fortify skill apparel Enchantments
- Weapon elemental damage enchantments
- Fortify skill potions
- Eight graduated weapon material tiers (nine with DG)
- Power attacks (which happen as long as Stamina >0 even if the amount normally consumed would push it below 0)
- Poisons
- Sneak attacks
Ways to increase Destruction damage:
- Dual casting (which drastically reduces mana/damage efficiency for a paltry gain in DPS)
- Higher tier spells (which have increasingly inefficient mana/damage ratios)
- Fortify skill potions
- Perks (6 perks for +50% from base spell magnitude (NO skill factor)for all elemental effects of Destruction)
- Dragon priest masks that only affects one particular element each (from Dragonborn) and also are not disenchantable
Ways you CANNOT increase destruction damage
- NOT base skill advancement
- NOT sneak attacks
- NOT having sufficient mana for ANY casting
- NO critical hits
- NOT apparel enchantments
- You can't weap-enchant a spell
- You can't smith a spell either
- Poisoning's out too
So... eleven ways to boost 1H/2H/Archery damage, and five ways to boost Destruction damage, only one of which doesn't have any caveats or shortfalls compared to any 1H/2H/Archery counterparts (IE: fortify potions).
Destruction does have a mobility advantage over Archery when preparing to fire... until that Ranger perk is acquired. Destruction lacks the sustained-fire ability of Archery, for the aforementioned magicka inefficiency problems consume magicka at an alarming rate, and the game throws arrows at you like confetti. And that mobility advantage vaporizes completely with the shining exemplars of Destruction's ineffectuality: the Master Spells, which root you in place when preparing to cast.
Speak up if I missed anything.
If Todd doesn't want the player to do "spreadsheet magic", then the onus is on the developers to do it for us. This is why Destruction is weak in the vanilla game: they didn't do it for us.