Lowering damage would only make the combat drag on even more. There's already a sense that I might have to sharpen my mace skills to ignore armor so I could just chop enemies quicker instead of trading blows for over 15 seconds. I'd say a good way to do it would be to revamp the perk something like:
Alchemist Skill Req: 0, 4/4 Ranks
Rank 1 (SR 0): Allow creation of potion from 2 ingredients, you must have this perk to perform alchemy.
Rank 2 (SR 25): Increase all potency of your mixtures by 5% and identifies an ingredient's 2nd effect upon consumption.
Rank 3 (SR 50): Increase all potency of your mixtures by 5% and identifies an ingredient's 3rd effect upon consumption.
Rank 4 (SR 75): Increase all potency of your mixtures by 5%, allows mixing of 3rd ingredient, and identifies an ingredient's entire effect upon consumption.
Rank 5 (SR 100): All mixtures receive 25% bonus, 25% chance of receiving additional dose when creating mixture, unlocks recipe: Transmute Iron to Gold.
Comment: I felt the 3 ingredient nature of the potions made it easy to stack up all the high value effect into one potion and then leveling up from consuming less raw materials. It levels so quickly and with the additional perk points unlock, the potion's effectiveness gets to the point where money becomes nearly irrelevant (allowing purchase from stores) and healing magic is unneeded because potions replace them so well with little fuss. With just 5% increments per tier, it won't feel like you're picking it up for the bonus effect, but to unlock more ingredient effect without meta-gaming or trial and error. Only at SR 75 do you gain the ability to mix an additional ingredient. Master skill seems lackluster but 20% to all means you gain 40% from not putting a single point on the specialized perks - and still receive an extra dose one out of four times. I consider that pretty high bonus.
Then branch things off from there:
Curatives SR 25, 3/3 Ranks
Rank 1 (25): HP/Mana/Stamina restoratives receive a 10% Boost
Rank 2 (50): HP/Mana/Stamina restoratives receive a 10% Boost, increase Poison & Disease Resistance by 25%
Rank 3 (75): HP/Mana/Stamina restoratives receive a 20% Boost, unlocks Lesser Power: Second Wind, summoning all your reserve energy, you regenerate 100% of your HP/MP/STA over 10 seconds, recharges every 24 hours.
Comment: 20% Boost to both HP/MP/STAM seems pretty sizeable to me. You do upgrade armor at roughly the same rate, and the cost of armor tends to be higher than alchemy. A simple blue flower and wheat harvesting and you end up with 10 bottles of curatives. Lesser Power is an idea I'm thinking - they should be rewarded for focusing on something - but what should it be? Since the Curative fans want more restoration magic substitute, let's give them that. A 'second chance' power once every day. I know it's not a big deal, but having 40% bonus to HP restoratives is already a huge boost, it doesn't deserve an even bigger bonus.
Venoms SR 25, 3/3 Ranks
Rank 1 (25): Venoms receive a 10% boost
Rank 2 (50): Venoms receive a 10% boost, poison application lasts for two strikes.
Rank 3 (75): Venoms receive a 20% boost, unlocks Lesser Power: Serpent's Fang, touch based attack that paralyzes for 3 seconds and deals 200 poison damage over 10 seconds, recharges every 24 hours.
Comment: I like poison. It nearly doubles your arrow damage at the start. Getting to 50 and unlocking double application translates to a nice stacking bonus. Finally mastering the venom gives you a direct attack power that deals poison and paralyze. Who uses venom? Mostly ranged assassins and thieves who needed an extra oomph at close range. The Lesser Power should give him a limited 'power' option when pushed to a corner. Yes, I am aware that it's an "I-win" button when facing 1 on 1 situations, but considering it takes 4 perks and 75 skill point to get there, it doesn't seem much. Who the hell picks the Stone of the Serpent Sign?
Enhancers SR 25, 3/3 Ranks
Rank 1 (25): Resistances & Buffs receive a 10% boost
Rank 2 (50): Resistances & Buffs receive a 10% boost, fire and frost resistance increased by 15%
Rank 3 (75): Resistances & Buffs receive a 20% boost, maximum health, magicka and stamina increased by 20.
Comment: This is not an essential perk to have, because these potion type's usage tend to be situational. You don't quaff Fire Resist / Fortify Sneak all the time etc. So why not reward the Enhancers specialists some type of permanence to their bonus? And if they're willing to take it all the way, they have a 6 levels worth of HP/MP/STA increment waiting for them. A Dunmer alchemist can easily hit 90% Resistance to Fire by the time they hit mid level alchemy from potion and its rank 2 perk. Nords too can achieve this with Frost.
I'm crazy. I know.