1) It's harder to do things that are vulgar, and failing them backfires hard. This applies to a lot of powerful effects, like throwing fireballs or turning into a tiger.
Both of those effects are worse than just adding a shitload of damage to a gun though.
Are they though? Let's say I want to throw a fireball. Fireball is Forces 3 Prime 2 (to create fire out of pure energy). I'm throwing it at a Syndicate Enforcer leading a squad of gangsters. This counts as Vulgar with witnesses because gangsters don't believe in magic. The difficulty is highest sphere +5. It nets out to Difficulty 8 with 3 dice, not the best odds. But that's ok, you might say. Every success on a forces attack leads to 2 points of damage, and every forces attack also gives you one extra damage. So if I succeed on all 3, I'm doing 7 damage. If I succeed on only 2 I do 5 damage. If I succeed on only 1 I still do 3 damage. If you succeed you take 4 points of paradox (one per highest sphere level for vulgar effects +1 for witnesses). If you botch you receive 8 points of paradox (2 points of paradox + 2 points per dot in highest sphere). And if you fail but don't botch you still take 4 for trying something vulgar with witnesses. So you're rolling against difficulty 8 with the best result being 7 damage to the enemy and 4 paradox for you, and the worst result being 0 damage to the enemy and 8 paradox for you. In the middle you only get 5 or 3 damage, but it
is aggravated (of course your opponent can still try and dodge the fireball, but then they'll be splitting dice pools).
What about turning into a tiger? Transform self is just Life 4. Still attacking the same Enforcer and his gangsters. Still Vulgar with witnesses. Difficulty=Highest Sphere+5=9. So rolling probably 4 dice (unless you are a higher arete then four, at with point you are supposed to be rare and powerful. Arete 5 costs 40 xp, Arete 6 costing 48, both of those cumulative on top of each other and the arete 4 cost of 32xp.) So you roll 4 dice against difficulty 9. Do you need a specific amount of successes to become a tiger? The rules say transforming yourself is a difficult magical feat, and so requires 3 successes. Regardless, You'll get 5 Paradox successful or not (10 if you botch). Tigers have (according to Bygone Bestiary) Claw for 6 dice, and Bite for 7.
A Heavy Revolver has 6 dice of damage. A good rifle/assault rifle will have 7-8 dice. A shotgun has 8 dice of damage. So the Enforcer is looking like he's the one better off, especially if he can get some extra damage dice through a good firearms skill or buffing the attack with his spheres somehow.
What if I want to rush him with Time 3 extra actions? This might be supposed to be vulgar, but the description doesn't say either way. However even if it's coincidental it's difficulty 6 and every extra action is two successes, plus you have to spend a success on duration. Assuming you only have 3-4 dice you're going to be spread pretty thin. You want to travel back in time to the beginning of the round to warn your buddy not to shoot a fireball because there's a tank of gasoline behind the enforcer that will bring down the building's main support, allowing the gangsters to escape? Also time 3, but the description explicitly refers to it as vulgar. That makes it difficulty 8. You need to spend a success to make it line of sight. It's likely a magical feat requiring more than one success on just the feat as well. It'd give the same paradox as the fireball, as both are vulgar with witnesses 3rd level sphere effects.
Honestly one of the better things you might do is to make a magical ban against bullets. It could be vulgar or coincidental depending on the circumstances. A force-field would be vulgar, as bullets pling off of it missing you. A prayer for protection, where the bullets simply sail by you could be coincidental. So if you're casting it as a prayer it shouldn't be that hard to protect your group from bullets with Correspondence 3 and Matter. You'd spend on the effect, area, and duration to get your whole party for the fight. But prayer is the kind of activity you can spend multiple rounds doing, so you could do it as a ritual to build successes if need be.
Honestly, minus the Correspondence wards, this looks a lot like the kinds of fights I've GMed. Except the guy who could turn into a tiger could also Time 3 extra actions, and he had help from the other party member with Time to get extra successes. It's not like such a fighting style can't work, you just need to realize that bad rolls could
screw over delay the plan and that you might come out with plenty of paradox. Being coincidental is always rewarded, but if you're willing to take a chance or pay willpower and spend quintessence to tip the odds you can make a more blunt force strategy work.
Mage rewards being prepared. If you knew the fight was coming you could pre-transform and pre-slow time. If you're squeamish about transforming, or just don't have Life 4 yet, buffing your stats with Life 3 is a nice thing to do when you have time. Then there's always the good old fashioned scry and die if you have Corr and Forces, though you'll need to collect a correspondence focus first (which could be work in and of itself).
If you're really worried that someone will catch you off guard, the Order of Hermes has a rote "Parma Magica" that banks quintessence into a 'shield' which you can spend to counter magic successes against you. Other ways to stay on your guard are basic Time 2 divinations, and Correspondence warding against scrying and Bans against ranged attacks.
