The footage used whilst Clark is speed running to save Lex from Van is the same footage that was used in S02 E08 ("Ryan") when Clark is rushing to reach Dr. Burton before his plan leaves. You can tell by the paperwork in Clark's back pocket in both scenes.
In this and other episodes, people are shown smelting meteor rock over a regular fire - in this episode Van McNulty uses a campfire flame to turn the meteor rock from a solid to a molten liquid. Meteors go through extreme heat when traveling through the Earth's atmosphere, much higher than that generated by a campfire.
Lead is a soft metal, and would be a poor choice for anti-bullet armor. Even if reinforced by Clark's power, as tight-fitting clothes often are in Superman comics and media, it would be a suspicious choice for anyone not aware of them. Yet Lana never remarks on it, even after she had time to think of the matter.