It sounds like you have the card info sorted out. The point of borrowing the profile of the older card is that you don't have to add the 1050 ti to graphicsrules, because that's the part that can throw people off, and the game doesn't care that its database name doesn't match your card. (Also, not that it matters, but an Nvidia 580 is a much stronger card than a 650, with over twice as good a performance in some benchmarks.)
The texture memory shouldn't still list <>, although I'm not completely sure it matters. Did you put both the # and a space immediately in front of setb in the graphicsrules entry? It's probably not a big deal though if you can't figure out how to fix it.
Yes, go ahead and max out your graphics settings. I don't think TS3 sets everything to max for any card, but you can adjust things however you like. A 1050 ti should be able to handle ultra settings if you're playing at a 1920x1080 resolution. The two you may want to dial back are water and high-detail lots, as they're the most demanding and will stress the game engine even if your card is handling its workload just fine.
