Limiting yourself is not dumb imo. If one uses all the tools they can in a game to overcome challenges, then one can avoid those tools to increase the challenge.
I dont agree with you. Not being able to use axii upgrades (puppets) just because it makes me OP is not a good solution (specially for me that always used axii since W1 and love the signs builds).
Regarding researching builds, i didn't do that. Started a sign build, put some points in axii and igni until unlocked axii upgrade 2. Suddenly the games started to feel more and more easy (some quests still impose challenge and I still die in some parts). The point is that overall the game became less enjoyable, since the puppets just 1-hit-kill everything that passes near them.
For now, the best way is impose some challenges. Problem is that i have already changed my build 3 times (see original post)
Now i`m doing a swordsman build (as suggested by some folks). So far its good. But I miss my other builds. I love those skills and upgrades, just feel that they need a nerf (in a separate mode). Maybe CDPR will look into this, launch patch, or a dark mode or maybe they correct this in the enhanced edition. For now I`m liking the game despite combat balance.