I don't know if I have business leading some routes, but I do. Gear holds when I call for a take, but I have not taken a screamer on trad. People who clean my leads will more often say this piece is an awesome placement than this piece is total crap, but the latter happens too, so maybe I don't place consistently good gear. Maybe I place gear at times simply to push me through a section, even if it is poor placement. Part of the thrill I guess but not very smart. Best not to head above a questionable piece when starting out, but you can spend too much time and energy fiddling with stuff.
I find TR'ing climbs before leading them talks me out of a lead I could do sometimes.