Throwing swim jigs is my favorite thing to fish with. Can I set the hook hard like I did with braid. How do I know how much pressure I can put on the fish before line snaps? I fish in mostly in ponds that have big bass. If i set the drag correctly should I be okay or should I go back to braid? I love the less visiblity that fluro has bc I fish heavy pressured water most of the time.
To answer your questions about 12# fluoro:
There are a lot of variables that can cause line to break. If the fish has the bait way back in its throat and the line is rubbing against the teeth as you fight it, then 12 can break. Even 20 can break. If you have a good knot and you hook the fish in the upper lip or the corner of its mouth then you will have a hard time breaking 12# line UNLESS he gets around a stump or lily pad stem.
The only way to know how much pressure you can put on the fish before it breaks is to put pressure on the fish until it breaks and then don't put that much pressure on the next one!
The primary reason I use 17 to 20# fluoro is for the added insurance in the event I have a tiny nick in the line or the fish gets around something and I have to drag it out. When the fish start biting we all get excited and most of the time unhook a fish and throw right back out without retying. I am a fanatic about retying but I still occasionally get lazy and don't retie after a fish.
I will guarantee that if you hook a bass over 3# bass on a jig or soft plastic bait and he has it down in his mouth to where the line has rubbed against his teeth, there are tiny nicks on your line just above the hook. It happens every time. Once this happens, your 12# line is now 8 or 10# line. Look at it closely the next time you hook a fish and he has choked it.
If I only fished open water with no cover (never) I would use 12 as well. It casts great and is more manageable than heavier line but I fish mostly Fork where every cast your line is in contact with stumps, limbs, shell beds, etc. As you stated, you fish ponds with big bass. You will absolutely get more bites with 12 versus 15 or 20 but is it worth it?