An odd question - for a start, you'd probably be better off being a more delicate type of smith to get notice, such as a silver smith. To see the absolute extravagance of some Roman silverwork you can go to https://www.khanacademy.org/partner-content/getty-museum/antiquities/roman-silversmiths/a/the-roman-silversmith-drinking-cups-of-the-elite with a video of the process at https://www.khanacademy.org/partner-content/getty-museum/antiquities/roman-silversmiths/v/roman-silver-cup

A smith in history would likely have spent near to a lifetime at their craft to reach the levels of skill that were truly noteworthy - look at something like the Lycurgus Cup to see what I mean. It is truly staggering. Time and expose to the upper classes would see gained fame and attention, but it would take time. Getting the patronage of one of the equite class, or better senatorial class, would help with this. Of course, the best place to be for this would be Rome itself.

Regarding torture devices, rather macabre, are you referring to instruments like the rack, or iron maiden? If so, they're not Roman, and the iron maiden is completely anachronistic historically, appearing as a tourist curiosity in 17th century Germany. Greco-Roman torture was quite crude, with a lot of scourging, flaying, burning, crushing, some sawing under Caligula, and in the east I believe the truly horrific scaphism - none of which require advanced metalworking. The only one that might would be the semi-mythical account by Diodorus Siculus of the Bronze Bull of Phalaris, created by the inventor Perillos (big metal bull, put the victim in, set a fire underneath and roast them, the cries of the victim come out of a "speaker" in the bull's mouth that are distorted to sounds like an animals bellows). Be aware, that in that tale Phalaris is horrified by the concept, has Perillos thrown in his own device, half roasted, removed from it, then thrown from a cliff. Sic semper supurii.